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PerformanceCounterType Enumeration

Specifies the formula used to calculate the NextValue method for a PerformanceCounter instance.

Namespace:  System.Diagnostics
Assembly:  System (in System.dll)

'Declaration
Public Enumeration PerformanceCounterType
'Usage
Dim instance As PerformanceCounterType

Member nameDescription
NumberOfItems32An instantaneous counter that shows the most recently observed value. Used, for example, to maintain a simple count of items or operations.

Formula: None. Does not display an average, but shows the raw data as it is collected.

Counters of this type include Memory\Available Bytes.

NumberOfItems64An instantaneous counter that shows the most recently observed value. Used, for example, to maintain a simple count of a very large number of items or operations. It is the same as NumberOfItems32 except that it uses larger fields to accommodate larger values.

Formula: None. Does not display an average, but shows the raw data as it is collected.

NumberOfItemsHEX32An instantaneous counter that shows the most recently observed value in hexadecimal format. Used, for example, to maintain a simple count of items or operations.

Formula: None. Does not display an average, but shows the raw data as it is collected.

NumberOfItemsHEX64An instantaneous counter that shows the most recently observed value. Used, for example, to maintain a simple count of a very large number of items or operations. It is the same as NumberOfItemsHEX32 except that it uses larger fields to accommodate larger values.

Formula: None. Does not display an average, but shows the raw data as it is collected

RateOfCountsPerSecond32A difference counter that shows the average number of operations completed during each second of the sample interval. Counters of this type measure time in ticks of the system clock.

Formula: (N 1 - N 0) / ((D 1 -D 0) / F), where N 1 and N 0 are performance counter readings, D 1 and D 0 are their corresponding time readings, and F represents the number of ticks per second. Thus, the numerator represents the number of operations performed during the last sample interval, the denominator represents the number of ticks elapsed during the last sample interval, and F is the frequency of the ticks. The value of F is factored into the equation so that the result can be displayed in seconds.

Counters of this type include System\ File Read Operations/sec.

RateOfCountsPerSecond64A difference counter that shows the average number of operations completed during each second of the sample interval. Counters of this type measure time in ticks of the system clock. This counter type is the same as the RateOfCountsPerSecond32 type, but it uses larger fields to accommodate larger values to track a high-volume number of items or operations per second, such as a byte-transmission rate.

Formula: (N 1 - N 0) / ((D 1 -D 0) / F), where N 1 and N 0 are performance counter readings, D 1 and D 0 are their corresponding time readings, and F represents the number of ticks per second. Thus, the numerator represents the number of operations performed during the last sample interval, the denominator represents the number of ticks elapsed during the last sample interval, and F is the frequency of the ticks. The value of F is factored into the equation so that the result can be displayed in seconds.

Counters of this type include System\ File Read Bytes/sec.

CountPerTimeInterval32An average counter designed to monitor the average length of a queue to a resource over time. It shows the difference between the queue lengths observed during the last two sample intervals divided by the duration of the interval. This type of counter is typically used to track the number of items that are queued or waiting.

Formula: (N 1 - N 0) / (D 1 - D 0), where the numerator represents the number of items in the queue and the denominator represents the time elapsed during the last sample interval.

CountPerTimeInterval64An average counter that monitors the average length of a queue to a resource over time. Counters of this type display the difference between the queue lengths observed during the last two sample intervals, divided by the duration of the interval. This counter type is the same as CountPerTimeInterval32 except that it uses larger fields to accommodate larger values. This type of counter is typically used to track a high-volume or very large number of items that are queued or waiting.

Formula: (N 1 - N 0) / (D 1 - D 0), where the numerator represents the number of items in a queue and the denominator represents the time elapsed during the sample interval.

RawFractionAn instantaneous percentage counter that shows the ratio of a subset to its set as a percentage. For example, it compares the number of bytes in use on a disk to the total number of bytes on the disk. Counters of this type display the current percentage only, not an average over time.

Formula: (N 0 / D 0) x 100, where D 0 represents a measured attribute (using a base counter of type RawBase) and N 0 represents one component of that attribute.

Counters of this type include Paging File\% Usage Peak.

RawBaseA base counter that stores the denominator of a counter that presents a general arithmetic fraction. Check that this value is greater than zero before using it as the denominator in a RawFraction value calculation.
AverageTimer32An average counter that measures the time it takes, on average, to complete a process or operation. Counters of this type display a ratio of the total elapsed time of the sample interval to the number of processes or operations completed during that time. This counter type measures time in ticks of the system clock.

Formula: ((N 1 -N 0)/F)/(B 1 -B 0), where N 1 and N 0 are performance counter readings, B 1 and B 0 are their corresponding AverageBase values, and F is the number of ticks per second. The value of F is factored into the equation so that the result can be displayed in seconds. Thus, the numerator represents the numbers of ticks counted during the last sample interval, F represents the frequency of the ticks, and the denominator represents the number of operations completed during the last sample interval.

Counters of this type include PhysicalDisk\ Avg. Disk sec/Transfer.

AverageBaseA base counter that is used in the calculation of time or count averages, such as AverageTimer32 and AverageCount64. Stores the denominator for calculating a counter to present "time per operation" or "count per operation".
AverageCount64An average counter that shows how many items are processed, on average, during an operation. Counters of this type display a ratio of the items processed to the number of operations completed. The ratio is calculated by comparing the number of items processed during the last interval to the number of operations completed during the last interval.

Formula: (N 1 -N 0)/(B 1 -B 0), where N 1 and N 0 are performance counter readings, and the B 1 and B 0 are their corresponding AverageBase values. Thus, the numerator represents the numbers of items processed during the sample interval, and the denominator represents the number of operations completed during the sample interval.

Counters of this type include PhysicalDisk\ Avg. Disk Bytes/Transfer.

SampleFractionA percentage counter that shows the average ratio of hits to all operations during the last two sample intervals.

Formula: ((N 1 - N 0) / (D 1 - D 0)) x 100, where the numerator represents the number of successful operations during the last sample interval, and the denominator represents the change in the number of all operations (of the type measured) completed during the sample interval, using counters of type SampleBase.

Counters of this type include Cache\Pin Read Hits %.

SampleCounterAn average counter that shows the average number of operations completed in one second. When a counter of this type samples the data, each sampling interrupt returns one or zero. The counter data is the number of ones that were sampled. It measures time in units of ticks of the system performance timer.

Formula: (N 1 – N 0) / ((D 1 – D 0) / F), where the numerator (N) represents the number of operations completed, the denominator (D) represents elapsed time in units of ticks of the system performance timer, and F represents the number of ticks that elapse in one second. F is factored into the equation so that the result can be displayed in seconds.

SampleBaseA base counter that stores the number of sampling interrupts taken and is used as a denominator in the sampling fraction. The sampling fraction is the number of samples that were 1 (or true) for a sample interrupt. Check that this value is greater than zero before using it as the denominator in a calculation of SampleFraction.
CounterTimerA percentage counter that shows the average time that a component is active as a percentage of the total sample time.

Formula: (N 1 - N 0) / (D 1 - D 0), where N 1 and N 0 are performance counter readings, and D 1 and D 0 are their corresponding time readings. Thus, the numerator represents the portions of the sample interval during which the monitored components were active, and the denominator represents the total elapsed time of the sample interval.

CounterTimerInverseA percentage counter that displays the average percentage of active time observed during sample interval. The value of these counters is calculated by monitoring the percentage of time that the service was inactive and then subtracting that value from 100 percent.

This is an inverse counter type. Inverse counters measure the time that a component is note active and derive the active time from that measurement. This counter type is the same as CounterTimer100NsInv except that it measures time in units of ticks of the system performance timer rather than in 100 nanosecond units.

Formula: (1- ((N 1 - N 0) / (D 1 - D 0))) x 100, where the numerator represents the time during the interval when the monitored components were inactive, and the denominator represents the total elapsed time of the sample interval.

Timer100NsA percentage counter that shows the active time of a component as a percentage of the total elapsed time of the sample interval. It measures time in units of 100 nanoseconds (ns). Counters of this type are designed to measure the activity of one component at a time.

Formula: (N 1 - N 0) / (D 1 - D 0) x 100, where the numerator represents the portions of the sample interval during which the monitored components were active, and the denominator represents the total elapsed time of the sample interval.

Counters of this type include Processor\ % User Time.

Timer100NsInverseA percentage counter that shows the average percentage of active time observed during the sample interval.

This is an inverse counter. Counters of this type calculate active time by measuring the time that the service was inactive and then subtracting the percentage of active time from 100 percent.

Formula: (1- ((N 1 - N 0) / (D 1 - D 0))) x 100, where the numerator represents the time during the interval when the monitored components were inactive, and the denominator represents the total elapsed time of the sample interval.

Counters of this type include Processor\ % Processor Time.

ElapsedTimeA difference timer that shows the total time between when the component or process started and the time when this value is calculated.

Formula: (D 0 - N 0) / F, where D 0 represents the current time, N 0 represents the time the object was started, and F represents the number of time units that elapse in one second. The value of F is factored into the equation so that the result can be displayed in seconds.

Counters of this type include System\ System Up Time.

CounterMultiTimerA percentage counter that displays the active time of one or more components as a percentage of the total time of the sample interval. Because the numerator records the active time of components operating simultaneously, the resulting percentage can exceed 100 percent.

This counter is a multitimer. Multitimers collect data from more than one instance of a component, such as a processor or disk. This counter type differs from CounterMultiTimer100Ns in that it measures time in units of ticks of the system performance timer, rather than in 100 nanosecond units.

Formula: ((N 1 - N 0) / (D 1 - D 0)) x 100 / B, where N 1 and N 0 are performance counter readings, D 1 and D 0 are their corresponding time readings in ticks of the system performance timer, and the variable B denotes the base count for the monitored components (using a base counter of type CounterMultiBase). Thus, the numerator represents the portions of the sample interval during which the monitored components were active, and the denominator represents the total elapsed time of the sample interval.

CounterMultiTimerInverseA percentage counter that shows the active time of one or more components as a percentage of the total time of the sample interval. It derives the active time by measuring the time that the components were not active and subtracting the result from 100 percent by the number of objects monitored.

This counter type is an inverse multitimer. Multitimers monitor more than one instance of a component, such as a processor or disk. Inverse counters measure the time that a component is not active and derive its active time from that measurement.

This counter differs from CounterMultiTimer100NsInverse in that it measures time in units of ticks of the system performance timer, rather than in 100 nanosecond units.

Formula: (B- ((N 1 - N 0) / (D 1 - D 0))) x 100, where the denominator represents the total elapsed time of the sample interval, the numerator represents the time during the interval when monitored components were inactive, and B represents the number of components being monitored, using a base counter of type CounterMultiBase.

CounterMultiTimer100NsA percentage counter that shows the active time of one or more components as a percentage of the total time of the sample interval. It measures time in 100 nanosecond (ns) units.

This counter type is a multitimer. Multitimers are designed to monitor more than one instance of a component, such as a processor or disk.

Formula: ((N 1 - N 0) / (D 1 - D 0)) x 100 / B, where N 1 and N 0 are performance counter readings, D 1 and D 0 are their corresponding time readings in 100-nanosecond units, and the variable B denotes the base count for the monitored components (using a base counter of type CounterMultiBase). Thus, the numerator represents the portions of the sample interval during which the monitored components were active, and the denominator represents the total elapsed time of the sample interval.

CounterMultiTimer100NsInverseA percentage counter that shows the active time of one or more components as a percentage of the total time of the sample interval. Counters of this type measure time in 100 nanosecond (ns) units. They derive the active time by measuring the time that the components were not active and subtracting the result from multiplying 100 percent by the number of objects monitored.

This counter type is an inverse multitimer. Multitimers are designed to monitor more than one instance of a component, such as a processor or disk. Inverse counters measure the time that a component is not active and derive its active time from the measurement of inactive time

Formula: (B - ((N 1 - N 0) / (D 1 - D 0))) x 100, where the denominator represents the total elapsed time of the sample interval, the numerator represents the time during the interval when monitored components were inactive, and B represents the number of components being monitored, using a base counter of type CounterMultiBase.

CounterMultiBaseA base counter that indicates the number of items sampled. It is used as the denominator in the calculations to get an average among the items sampled when taking timings of multiple, but similar items. Used with CounterMultiTimer, CounterMultiTimerInverse, CounterMultiTimer100Ns, and CounterMultiTimer100NsInverse.
CounterDelta32A difference counter that shows the change in the measured attribute between the two most recent sample intervals.

Formula: N 1 -N 0, where N 1 and N 0 are performance counter readings.

CounterDelta64A difference counter that shows the change in the measured attribute between the two most recent sample intervals. It is the same as the CounterDelta32 counter type except that is uses larger fields to accomodate larger values.

Formula: N 1 -N 0, where N 1 and N 0 are performance counter readings.

Some counter types represent raw data, while others represent calculated values that are based on one or more counter samples. The following categories classify the types of counters available.

  • Average: measure a value over time and display the average of the last two measurements. Associated with each average counter is a base counter that tracks the number of samples involved.

  • Difference: subtract the last measurement from the previous one and display the difference, if it is positive; if negative, they display a zero.

  • Instantaneous: display the most recent measurement.

  • Percentage: display calculated values as a percentage.

  • Rate: sample an increasing count of events over time and divide the change in count values by the change in time to display a rate of activity.

When sampling performance counter data, using a counter type that represents an average can make raw data values meaningful for your use. For example, the raw data counter NumberOfItems64 can expose data that is fairly random from sample to sample. The formula for an average calculation of the values that the counter returns would be (X 0 +X 1 +…+X n)/n, where each X i is a raw counter sample.

Rate counters are similar to average counters, but more useful for situations in which the rate increases as a resource is used. A formula that quickly calculates the average is ((X n -X 0)/(T n -T 0)) / frequency, where each X i is a counter sample and each T i is the time that the corresponding sample was taken. The result is the average usage per second.

NoteNote:

Unless otherwise indicated, the time base is seconds.

When instrumenting applications (creating and writing custom performance counters), you might be working with performance counter types that rely on an accompanying base counter that is used in the calculations. The base counter must be immediately after its associated counter in the CounterCreationDataCollection collection your application uses. The following table lists the base counter types with their corresponding performance counter types.

Base counter type

Performance counter types

AverageBase

AverageTimer32

AverageCount64

CounterMultiBase

CounterMultiTimer

CounterMultiTimerInverse

CounterMultiTimer100Ns

CounterMultiTimer100NsInverse

RawBase

RawFraction

SampleBase

SampleFraction

The following examples demonstrate several of the counter types in the PerformanceCounterType enumeration.

AverageCount64

Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics

 _

Public Class App

    Private Shared avgCounter64Sample As PerformanceCounter
    Private Shared avgCounter64SampleBase As PerformanceCounter


    Public Shared Sub Main()

        Dim samplesList As New ArrayList()
        'If the category does not exist, create the category and exit. 
        'Performance counters should not be created and immediately used. 
        'There is a latency time to enable the counters, they should be created 
        'prior to executing the application that uses the counters. 
        'Execute this sample a second time to use the counters. 
        If Not (SetupCategory()) Then
            CreateCounters()
            CollectSamples(samplesList)
            CalculateResults(samplesList)
        End If 

    End Sub 'Main



    Private Shared Function SetupCategory() As Boolean 
        If Not PerformanceCounterCategory.Exists("AverageCounter64SampleCategory") Then 

            Dim counterDataCollection As New CounterCreationDataCollection()

            ' Add the counter. 
            Dim averageCount64 As New CounterCreationData()
            averageCount64.CounterType = PerformanceCounterType.AverageCount64
            averageCount64.CounterName = "AverageCounter64Sample"
            counterDataCollection.Add(averageCount64)

            ' Add the base counter. 
            Dim averageCount64Base As New CounterCreationData()
            averageCount64Base.CounterType = PerformanceCounterType.AverageBase
            averageCount64Base.CounterName = "AverageCounter64SampleBase"
            counterDataCollection.Add(averageCount64Base)

            ' Create the category.
            PerformanceCounterCategory.Create("AverageCounter64SampleCategory", _
               "Demonstrates usage of the AverageCounter64 performance counter type.", _
                      PerformanceCounterCategoryType.SingleInstance, counterDataCollection)


            Return True 
        Else
            Console.WriteLine("Category exists - AverageCounter64SampleCategory")
            Return False 
        End If 
    End Function 'SetupCategory


    Private Shared Sub CreateCounters()
        ' Create the counters.

        avgCounter64Sample = New PerformanceCounter("AverageCounter64SampleCategory", "AverageCounter64Sample", False)

        avgCounter64SampleBase = New PerformanceCounter("AverageCounter64SampleCategory", "AverageCounter64SampleBase", False)


        avgCounter64Sample.RawValue = 0
        avgCounter64SampleBase.RawValue = 0
    End Sub 'CreateCounters

    Private Shared Sub CollectSamples(ByVal samplesList As ArrayList)

        Dim r As New Random(DateTime.Now.Millisecond)

        ' Loop for the samples. 
        Dim j As Integer 
        For j = 0 To 99

            Dim value As Integer = r.Next(1, 10)
            Console.Write(j.ToString() + " = " + value.ToString())

            avgCounter64Sample.IncrementBy(value)

            avgCounter64SampleBase.Increment()

            If j Mod 10 = 9 Then
                OutputSample(avgCounter64Sample.NextSample())
                samplesList.Add(avgCounter64Sample.NextSample())
            Else
                Console.WriteLine()
            End If
            System.Threading.Thread.Sleep(50)
        Next j
    End Sub 'CollectSamples

    Private Shared Sub CalculateResults(ByVal samplesList As ArrayList)
        Dim i As Integer 
        For i = 0 To (samplesList.Count - 1) - 1
            ' Output the sample.
            OutputSample(CType(samplesList(i), CounterSample))
            OutputSample(CType(samplesList((i + 1)), CounterSample))

            ' Use .NET to calculate the counter value.
            Console.WriteLine(".NET computed counter value = " + CounterSampleCalculator.ComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())

            ' Calculate the counter value manually.
            Console.WriteLine("My computed counter value = " + MyComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())
        Next i
    End Sub 'CalculateResults




    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    '	Description - This counter type shows how many items are processed, on average, 
    '		during an operation. Counters of this type display a ratio of the items  
    '		processed (such as bytes sent) to the number of operations completed. The   
    '		ratio is calculated by comparing the number of items processed during the  
    '		last interval to the number of operations completed during the last interval.  
    ' Generic type - Average 
    '  	Formula - (N1 - N0) / (D1 - D0), where the numerator (N) represents the number  
    '		of items processed during the last sample interval and the denominator (D)  
    '		represents the number of operations completed during the last two sample  
    '		intervals.  
    '	Average (Nx - N0) / (Dx - D0)   
    '	Example PhysicalDisk\ Avg. Disk Bytes/Transfer  
    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    Private Shared Function MyComputeCounterValue(ByVal s0 As CounterSample, ByVal s1 As CounterSample) As [Single]
        Dim numerator As [Single] = CType(s1.RawValue, [Single]) - CType(s0.RawValue, [Single])
        Dim denomenator As [Single] = CType(s1.BaseValue, [Single]) - CType(s0.BaseValue, [Single])
        Dim counterValue As [Single] = numerator / denomenator
        Return counterValue
    End Function 'MyComputeCounterValue


    ' Output information about the counter sample. 
    Private Shared Sub OutputSample(ByVal s As CounterSample)
        Console.WriteLine(ControlChars.Lf + ControlChars.Cr + "+++++++++++")
        Console.WriteLine("Sample values - " + ControlChars.Lf + ControlChars.Cr)
        Console.WriteLine(("   BaseValue        = " + s.BaseValue.ToString()))
        Console.WriteLine(("   CounterFrequency = " + s.CounterFrequency.ToString()))
        Console.WriteLine(("   CounterTimeStamp = " + s.CounterTimeStamp.ToString()))
        Console.WriteLine(("   CounterType      = " + s.CounterType.ToString()))
        Console.WriteLine(("   RawValue         = " + s.RawValue.ToString()))
        Console.WriteLine(("   SystemFrequency  = " + s.SystemFrequency.ToString()))
        Console.WriteLine(("   TimeStamp        = " + s.TimeStamp.ToString()))
        Console.WriteLine(("   TimeStamp100nSec = " + s.TimeStamp100nSec.ToString()))
        Console.WriteLine("++++++++++++++++++++++")
    End Sub 'OutputSample
End Class 'App

AverageTimer32

Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics
Imports System.Runtime.InteropServices
Imports Microsoft.VisualBasic

Public Class App

    Private Const categoryName As String = "AverageTimer32SampleCategory" 
    Private Const counterName As String = "AverageTimer32Sample" 
    Private Const baseCounterName As String = "AverageTimer32SampleBase" 

    Private Shared PC As PerformanceCounter
    Private Shared BPC As PerformanceCounter


    Public Shared Sub Main()
        Dim samplesList As New ArrayList()

        SetupCategory()
        CreateCounters()
        CollectSamples(samplesList)
        CalculateResults(samplesList)
    End Sub 


    Private Shared Function SetupCategory() As Boolean 

        If Not PerformanceCounterCategory.Exists(categoryName) Then 

            Dim CCDC As New CounterCreationDataCollection()

            ' Add the counter. 
            Dim averageTimer32 As New CounterCreationData()
            averageTimer32.CounterType = PerformanceCounterType.AverageTimer32
            averageTimer32.CounterName = counterName
            CCDC.Add(averageTimer32)

            ' Add the base counter. 
            Dim averageTimer32Base As New CounterCreationData()
            averageTimer32Base.CounterType = PerformanceCounterType.AverageBase
            averageTimer32Base.CounterName = baseCounterName
            CCDC.Add(averageTimer32Base)

            ' Create the category.
            PerformanceCounterCategory.Create( _
               categoryName, _
               "Demonstrates usage of the AverageTimer32 performance counter type", _
                 PerformanceCounterCategoryType.SingleInstance, CCDC)

            Console.WriteLine("Category created - " + categoryName)

            Return True 
        Else
            Console.WriteLine(("Category exists - " + _
               categoryName))
            Return False 
        End If 
    End Function 


    Private Shared Sub CreateCounters()
        ' Create the counters.
        PC = New PerformanceCounter(categoryName, _
              counterName, False)

        BPC = New PerformanceCounter(categoryName, _
              baseCounterName, False)

        PC.RawValue = 0
        BPC.RawValue = 0
    End Sub 


    Private Shared Sub CollectSamples(ByVal samplesList As ArrayList)

        Dim r As New Random(DateTime.Now.Millisecond)

        ' Loop for the samples. 
        Dim i As Integer 
        For i = 0 To 9

            PC.RawValue = Stopwatch.GetTimeStamp()

            BPC.IncrementBy(10)

            System.Threading.Thread.Sleep(1000)
            Console.WriteLine(("Next value = " + PC.NextValue().ToString()))
            samplesList.Add(PC.NextSample())
        Next i
    End Sub 


    Private Shared Sub CalculateResults(ByVal samplesList As ArrayList)
        Dim i As Integer 
        Dim sample1 As CounterSample
        Dim sample2 As CounterSample
        For i = 0 To (samplesList.Count - 1) - 1
            ' Output the sample.
            sample1 = CType(samplesList(i), CounterSample)
            sample2 = CType(samplesList(i + 1), CounterSample)
            OutputSample(sample1)
            OutputSample(sample2)

            ' Use .NET to calculate the counter value.
            Console.WriteLine((".NET computed counter value = " _
               + CounterSample.Calculate(sample1, sample2).ToString()))

            ' Calculate the counter value manually.
            Console.WriteLine(("My computed counter value = " _
               + MyComputeCounterValue(sample1, sample2).ToString()))

        Next i
    End Sub 


    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//+++++++ 
    ' PERF_AVERAGE_TIMER 
    '  Description - This counter type measures the time it takes, on  
    '     average, to complete a process or operation. Counters of this 
    '     type display a ratio of the total elapsed time of the sample  
    '     interval to the number of processes or operations completed 
    '     during that time. This counter type measures time in ticks  
    '     of the system clock. The F variable represents the number of 
    '     ticks per second. The value of F is factored into the equation 
    '     so that the result can be displayed in seconds. 
    
    '  Generic type - Average 
    
    '  Formula - ((N1 - N0) / F) / (D1 - D0), where the numerator (N) 
    '     represents the number of ticks counted during the last  
    '     sample interval, F represents the frequency of the ticks,  
    '     and the denominator (D) represents the number of operations 
    '     completed during the last sample interval. 
    
    '  Average - ((Nx - N0) / F) / (Dx - D0) 
    
    '  Example - PhysicalDisk\ Avg. Disk sec/Transfer  
    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//+++++++ 
    Private Shared Function MyComputeCounterValue( _
    ByVal s0 As CounterSample, _
    ByVal s1 As CounterSample) As Single
        Dim n1 As Int64 = s1.RawValue
        Dim n0 As Int64 = s0.RawValue
        Dim f As Decimal = CType(s1.SystemFrequency, Decimal)
        Dim d1 As Int64 = s1.BaseValue
        Dim d0 As Int64 = s0.BaseValue

        Dim numerator As Double = System.Convert.ToDouble(n1 - n0)
        Dim denominator As Double = System.Convert.ToDouble(d1 - d0)
        Dim counterValue As Single = CType(numerator, Single)
        counterValue = counterValue / CType(f, Single)
        counterValue = counterValue / CType(denominator, Single)

        Return counterValue
    End Function 


    ' Output information about the counter sample. 
    Private Shared Sub OutputSample(ByVal s As CounterSample)
        Console.WriteLine("+++++++++++")
        Console.WriteLine("Sample values - " + ControlChars.Cr _
              + ControlChars.Lf)
        Console.WriteLine(("   CounterType      = " + _
              s.CounterType.ToString()))
        Console.WriteLine(("   RawValue         = " + _
              s.RawValue.ToString()))
        Console.WriteLine(("   BaseValue        = " _
              + s.BaseValue.ToString()))
        Console.WriteLine(("   CounterFrequency = " + _
              s.CounterFrequency.ToString()))
        Console.WriteLine(("   CounterTimeStamp = " + _
              s.CounterTimeStamp.ToString()))
        Console.WriteLine(("   SystemFrequency  = " + _
              s.SystemFrequency.ToString()))
        Console.WriteLine(("   TimeStamp        = " + _
              s.TimeStamp.ToString()))
        Console.WriteLine(("   TimeStamp100nSec = " + _
              s.TimeStamp100nSec.ToString()))
        Console.WriteLine("++++++++++++++++++++++")
    End Sub 


End Class

ElapsedTime

Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics
Imports System.Runtime.InteropServices
Imports Microsoft.VisualBasic

Public Class App

    Public Shared Sub Main()
        CollectSamples()
    End Sub 

    Private Shared Sub CollectSamples()

        Dim categoryName As String = "ElapsedTimeSampleCategory" 
        Dim counterName As String = "ElapsedTimeSample" 

        If Not PerformanceCounterCategory.Exists(categoryName) Then 

            Dim CCDC As New CounterCreationDataCollection()

            ' Add the counter. 
            Dim ETimeData As New CounterCreationData()
            ETimeData.CounterType = PerformanceCounterType.ElapsedTime
            ETimeData.CounterName = counterName
            CCDC.Add(ETimeData)

            ' Create the category.
            PerformanceCounterCategory.Create(categoryName, _
               "Demonstrates ElapsedTime performance counter usage.", _
                   PerformanceCounterCategoryType.SingleInstance, CCDC)

        Else
            Console.WriteLine("Category exists - {0}", categoryName)
        End If 

        ' Create the counter. 
        Dim PC As PerformanceCounter
        PC = New PerformanceCounter(categoryName, counterName, False)

        ' Initialize the counter.
        PC.RawValue = Stopwatch.GetTimestamp()

        Dim Start As DateTime = DateTime.Now

        ' Loop for the samples. 
        Dim j As Integer 
        For j = 0 To 99
            ' Output the values. 
            If j Mod 10 = 9 Then
                Console.WriteLine(("NextValue() = " _
                    + PC.NextValue().ToString()))
                Console.WriteLine(("Actual elapsed time = " _
                    + DateTime.Now.Subtract(Start).ToString()))
                OutputSample(PC.NextSample())
            End If 

            ' Reset the counter every 20th iteration. 
            If j Mod 20 = 0 Then
                PC.RawValue = Stopwatch.GetTimestamp()
                Start = DateTime.Now
            End If
            System.Threading.Thread.Sleep(50)
        Next j

        Console.WriteLine(("Elapsed time = " + _
              DateTime.Now.Subtract(Start).ToString()))
    End Sub 


    Private Shared Sub OutputSample(ByVal s As CounterSample)
        Console.WriteLine(ControlChars.Lf + ControlChars.Cr + "+++++++")

        Console.WriteLine("Sample values - " + ControlChars.Cr _
              + ControlChars.Lf)
        Console.WriteLine(("   BaseValue        = " _
              + s.BaseValue.ToString()))
        Console.WriteLine(("   CounterFrequency = " + _
              s.CounterFrequency.ToString()))
        Console.WriteLine(("   CounterTimeStamp = " + _
              s.CounterTimeStamp.ToString()))
        Console.WriteLine(("   CounterType      = " + _
              s.CounterType.ToString()))
        Console.WriteLine(("   RawValue         = " + _
              s.RawValue.ToString()))
        Console.WriteLine(("   SystemFrequency  = " + _
              s.SystemFrequency.ToString()))
        Console.WriteLine(("   TimeStamp        = " + _
              s.TimeStamp.ToString()))
        Console.WriteLine(("   TimeStamp100nSec = " + _
              s.TimeStamp100nSec.ToString()))

        Console.WriteLine("+++++++")
    End Sub 
End Class

NumberOfItems32

Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics

 _

Public Class NumberOfItems64

    Private Shared PC As PerformanceCounter


    Public Shared Sub Main()
        Dim samplesList As New ArrayList()
        'If the category does not exist, create the category and exit. 
        'Performance counters should not be created and immediately used. 
        'There is a latency time to enable the counters, they should be created 
        'prior to executing the application that uses the counters. 
        'Execute this sample a second time to use the counters. 
        If Not (SetupCategory()) Then
            CreateCounters()
            CollectSamples(samplesList)
            CalculateResults(samplesList)
        End If 
    End Sub 'Main


    Private Shared Function SetupCategory() As Boolean 
        If Not PerformanceCounterCategory.Exists("NumberOfItems32SampleCategory") Then 

            Dim CCDC As New CounterCreationDataCollection()

            ' Add the counter. 
            Dim NOI64 As New CounterCreationData()
            NOI64.CounterType = PerformanceCounterType.NumberOfItems64
            NOI64.CounterName = "NumberOfItems32Sample"
            CCDC.Add(NOI64)

            ' Create the category.
            PerformanceCounterCategory.Create("NumberOfItems32SampleCategory", _
            "Demonstrates usage of the NumberOfItems32 performance counter type.", _
                      PerformanceCounterCategoryType.SingleInstance, CCDC)

            Return True 
        Else
            Console.WriteLine("Category exists - NumberOfItems32SampleCategory")
            Return False 
        End If 
    End Function 'SetupCategory


    Private Shared Sub CreateCounters()
        ' Create the counter.
        PC = New PerformanceCounter("NumberOfItems32SampleCategory", "NumberOfItems32Sample", False)

        PC.RawValue = 0
    End Sub 'CreateCounters


    Private Shared Sub CollectSamples(ByVal samplesList As ArrayList)



        Dim r As New Random(DateTime.Now.Millisecond)

        ' Loop for the samples. 
        Dim j As Integer 
        For j = 0 To 99

            Dim value As Integer = r.Next(1, 10)
            Console.Write(j.ToString() + " = " + value.ToString())

            PC.IncrementBy(value)

            If j Mod 10 = 9 Then
                OutputSample(PC.NextSample())
                samplesList.Add(PC.NextSample())
            Else
                Console.WriteLine()
            End If
            System.Threading.Thread.Sleep(50)
        Next j
    End Sub 'CollectSamples




    Private Shared Sub CalculateResults(ByVal samplesList As ArrayList)
        Dim i As Integer 
        For i = 0 To (samplesList.Count - 1) - 1
            ' Output the sample.
            OutputSample(CType(samplesList(i), CounterSample))
            OutputSample(CType(samplesList((i + 1)), CounterSample))

            ' Use .NET to calculate the counter value.
            Console.WriteLine(".NET computed counter value = " + CounterSampleCalculator.ComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())

            ' Calculate the counter value manually.
            Console.WriteLine("My computed counter value = " + MyComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())
        Next i
    End Sub 'CalculateResults




    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    Private Shared Function MyComputeCounterValue(ByVal s0 As CounterSample, ByVal s1 As CounterSample) As [Single]
        Dim counterValue As [Single] = s1.RawValue
        Return counterValue
    End Function 'MyComputeCounterValue


    ' Output information about the counter sample. 
    Private Shared Sub OutputSample(ByVal s As CounterSample)
        Console.WriteLine(ControlChars.Lf + ControlChars.Cr + "+++++++++++")
        Console.WriteLine("Sample values - " + ControlChars.Lf + ControlChars.Cr)
        Console.WriteLine("   BaseValue        = " + s.BaseValue.ToString())
        Console.WriteLine("   CounterFrequency = " + s.CounterFrequency.ToString())
        Console.WriteLine("   CounterTimeStamp = " + s.CounterTimeStamp.ToString())
        Console.WriteLine("   CounterType      = " + s.CounterType.ToString())
        Console.WriteLine("   RawValue         = " + s.RawValue.ToString())
        Console.WriteLine("   SystemFrequency  = " + s.SystemFrequency.ToString())
        Console.WriteLine("   TimeStamp        = " + s.TimeStamp.ToString())
        Console.WriteLine("   TimeStamp100nSec = " + s.TimeStamp100nSec.ToString())
        Console.WriteLine("++++++++++++++++++++++")
    End Sub 'OutputSample
End Class 'NumberOfItems64 

NumberOfItems64

Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics

 _

Public Class NumberOfItems64

    Private Shared PC As PerformanceCounter


    Public Shared Sub Main()
        Dim samplesList As New ArrayList()

        'If the category does not exist, create the category and exit. 
        'Performance counters should not be created and immediately used. 
        'There is a latency time to enable the counters, they should be created 
        'prior to executing the application that uses the counters. 
        'Execute this sample a second time to use the counters. 
        If Not (SetupCategory()) Then
            CreateCounters()
            CollectSamples(samplesList)
            CalculateResults(samplesList)
        End If 

    End Sub 'Main


    Private Shared Function SetupCategory() As Boolean 
        If Not PerformanceCounterCategory.Exists("NumberOfItems64SampleCategory") Then 

            Dim CCDC As New CounterCreationDataCollection()

            ' Add the counter. 
            Dim NOI64 As New CounterCreationData()
            NOI64.CounterType = PerformanceCounterType.NumberOfItems64
            NOI64.CounterName = "NumberOfItems64Sample"
            CCDC.Add(NOI64)

            ' Create the category.
            PerformanceCounterCategory.Create("NumberOfItems64SampleCategory", _
            "Demonstrates usage of the NumberOfItems64 performance counter type.", _
                   PerformanceCounterCategoryType.SingleInstance, CCDC)

            Return True 
        Else
            Console.WriteLine("Category exists - NumberOfItems64SampleCategory")
            Return False 
        End If 
    End Function 'SetupCategory


    Private Shared Sub CreateCounters()
        ' Create the counters.
        PC = New PerformanceCounter("NumberOfItems64SampleCategory", "NumberOfItems64Sample", False)

        PC.RawValue = 0
    End Sub 'CreateCounters


    Private Shared Sub CollectSamples(ByVal samplesList As ArrayList)

        Dim r As New Random(DateTime.Now.Millisecond)

        ' Loop for the samples. 
        Dim j As Integer 
        For j = 0 To 99

            Dim value As Integer = r.Next(1, 10)
            Console.Write((j.ToString() + " = " + value.ToString()))

            PC.IncrementBy(value)

            If j Mod 10 = 9 Then
                OutputSample(PC.NextSample())
                samplesList.Add(PC.NextSample())
            Else
                Console.WriteLine()
            End If
            System.Threading.Thread.Sleep(50)
        Next j
    End Sub 'CollectSamples


    Private Shared Sub CalculateResults(ByVal samplesList As ArrayList)
        Dim i As Integer 
        For i = 0 To (samplesList.Count - 1) - 1
            ' Output the sample.
            OutputSample(CType(samplesList(i), CounterSample))
            OutputSample(CType(samplesList((i + 1)), CounterSample))

            ' Use .NET to calculate the counter value.
            Console.WriteLine(".NET computed counter value = " + CounterSampleCalculator.ComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())

            ' Calculate the counter value manually.
            Console.WriteLine("My computed counter value = " + MyComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())
        Next i
    End Sub 'CalculateResults




    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    Private Shared Function MyComputeCounterValue(ByVal s0 As CounterSample, ByVal s1 As CounterSample) As [Single]
        Dim counterValue As [Single] = s1.RawValue
        Return counterValue
    End Function 'MyComputeCounterValue


    ' Output information about the counter sample. 
    Private Shared Sub OutputSample(ByVal s As CounterSample)
        Console.WriteLine(ControlChars.Lf + ControlChars.Cr + "+++++++++++")
        Console.WriteLine("Sample values - " + ControlChars.Lf + ControlChars.Cr)
        Console.WriteLine(("   BaseValue        = " + s.BaseValue.ToString()))
        Console.WriteLine(("   CounterFrequency = " + s.CounterFrequency.ToString()))
        Console.WriteLine(("   CounterTimeStamp = " + s.CounterTimeStamp.ToString()))
        Console.WriteLine(("   CounterType      = " + s.CounterType.ToString()))
        Console.WriteLine(("   RawValue         = " + s.RawValue.ToString()))
        Console.WriteLine(("   SystemFrequency  = " + s.SystemFrequency.ToString()))
        Console.WriteLine(("   TimeStamp        = " + s.TimeStamp.ToString()))
        Console.WriteLine(("   TimeStamp100nSec = " + s.TimeStamp100nSec.ToString()))
        Console.WriteLine("++++++++++++++++++++++")
    End Sub 'OutputSample
End Class 'NumberOfItems64 

RateOfCountsPerSecond32

Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics

 _

Public Class App
    Private Shared PC As PerformanceCounter


    Public Shared Sub Main()
        Dim samplesList As New ArrayList()

        'If the category does not exist, create the category and exit. 
        'Performance counters should not be created and immediately used. 
        'There is a latency time to enable the counters, they should be created 
        'prior to executing the application that uses the counters. 
        'Execute this sample a second time to use the counters. 
        If Not (SetupCategory()) Then
            CreateCounters()
            CollectSamples(samplesList)
            CalculateResults(samplesList)
        End If 
    End Sub 'Main


    Private Shared Function SetupCategory() As Boolean 

        If Not PerformanceCounterCategory.Exists("RateOfCountsPerSecond32SampleCategory") Then 


            Dim CCDC As New CounterCreationDataCollection()

            ' Add the counter. 
            Dim rateOfCounts32 As New CounterCreationData()
            rateOfCounts32.CounterType = PerformanceCounterType.RateOfCountsPerSecond32
            rateOfCounts32.CounterName = "RateOfCountsPerSecond32Sample"
            CCDC.Add(rateOfCounts32)

            ' Create the category.
            PerformanceCounterCategory.Create("RateOfCountsPerSecond32SampleCategory", _
                "Demonstrates usage of the RateOfCountsPerSecond32 performance counter type.", _
                PerformanceCounterCategoryType.SingleInstance, CCDC)
            Return True 
        Else
            Console.WriteLine("Category exists - RateOfCountsPerSecond32SampleCategory")
            Return False 
        End If 
    End Function 'SetupCategory


    Private Shared Sub CreateCounters()
        ' Create the counter.
        PC = New PerformanceCounter("RateOfCountsPerSecond32SampleCategory", "RateOfCountsPerSecond32Sample", False)

        PC.RawValue = 0
    End Sub 'CreateCounters


    Private Shared Sub CollectSamples(ByVal samplesList As ArrayList)

        Dim r As New Random(DateTime.Now.Millisecond)

        ' Initialize the performance counter.
        PC.NextSample()

        ' Loop for the samples. 
        Dim j As Integer 
        For j = 0 To 99

            Dim value As Integer = r.Next(1, 10)
            PC.IncrementBy(value)
            Console.Write((j.ToString() + " = " + value.ToString()))

            If j Mod 10 = 9 Then
                Console.WriteLine((";       NextValue() = " + PC.NextValue().ToString()))
                OutputSample(PC.NextSample())
                samplesList.Add(PC.NextSample())
            Else
                Console.WriteLine()
            End If
            System.Threading.Thread.Sleep(50)
        Next j
    End Sub 'CollectSamples


    Private Shared Sub CalculateResults(ByVal samplesList As ArrayList)
        Dim i As Integer 
        For i = 0 To (samplesList.Count - 1) - 1
            ' Output the sample.
            OutputSample(CType(samplesList(i), CounterSample))
            OutputSample(CType(samplesList((i + 1)), CounterSample))


            ' Use .NET to calculate the counter value.
            Console.WriteLine(".NET computed counter value = " + CounterSampleCalculator.ComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())

            ' Calculate the counter value manually.
            Console.WriteLine("My computed counter value = " + MyComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())
        Next i
    End Sub 'CalculateResults





    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    '	PERF_COUNTER_COUNTER 
    '	Description	 - This counter type shows the average number of operations completed 
    '		during each second of the sample interval. Counters of this type 
    '		measure time in ticks of the system clock. The F variable represents 
    '		the number of ticks per second. The value of F is factored into the 
    '		equation so that the result can be displayed in seconds. 
    
    '	Generic type - Difference 
    
    '	Formula - (N1 - N0) / ( (D1 - D0) / F), where the numerator (N) represents the number 
    '		of operations performed during the last sample interval, the denominator 
    '		(D) represents the number of ticks elapsed during the last sample 
    '		interval, and F is the frequency of the ticks. 
    
    '	     Average - (Nx - N0) / ((Dx - D0) / F)  
    
    '       Example - System\ File Read Operations/sec  
    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    Private Shared Function MyComputeCounterValue(ByVal s0 As CounterSample, ByVal s1 As CounterSample) As [Single]
        Dim numerator As [Single] = CType(s1.RawValue - s0.RawValue, [Single])
        Dim denomenator As [Single] = CType(s1.TimeStamp - s0.TimeStamp, [Single]) / CType(s1.SystemFrequency, [Single])
        Dim counterValue As [Single] = numerator / denomenator
        Return counterValue
    End Function 'MyComputeCounterValue


    ' Output information about the counter sample. 
    Private Shared Sub OutputSample(ByVal s As CounterSample)
        Console.WriteLine(ControlChars.Lf + ControlChars.Cr + "+++++++++++")
        Console.WriteLine("Sample values - " + ControlChars.Lf + ControlChars.Cr)
        Console.WriteLine(("   BaseValue        = " + s.BaseValue.ToString()))
        Console.WriteLine(("   CounterFrequency = " + s.CounterFrequency.ToString()))
        Console.WriteLine(("   CounterTimeStamp = " + s.CounterTimeStamp.ToString()))
        Console.WriteLine(("   CounterType      = " + s.CounterType.ToString()))
        Console.WriteLine(("   RawValue         = " + s.RawValue.ToString()))
        Console.WriteLine(("   SystemFrequency  = " + s.SystemFrequency.ToString()))
        Console.WriteLine(("   TimeStamp        = " + s.TimeStamp.ToString()))
        Console.WriteLine(("   TimeStamp100nSec = " + s.TimeStamp100nSec.ToString()))
        Console.WriteLine("++++++++++++++++++++++")
    End Sub 'OutputSample
End Class 'App 

RateOfCountsPerSecond64

Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics

 _

Public Class App
    Private Shared PC As PerformanceCounter


    Public Shared Sub Main()
        Dim samplesList As New ArrayList()
        'If the category does not exist, create the category and exit. 
        'Performance counters should not be created and immediately used. 
        'There is a latency time to enable the counters, they should be created 
        'prior to executing the application that uses the counters. 
        'Execute this sample a second time to use the counters. 
        If Not (SetupCategory()) Then
            CreateCounters()
            CollectSamples(samplesList)
            CalculateResults(samplesList)
        End If 
    End Sub 'Main


    Private Shared Function SetupCategory() As Boolean 


        If Not PerformanceCounterCategory.Exists("RateOfCountsPerSecond64SampleCategory") Then 


            Dim CCDC As New CounterCreationDataCollection()

            ' Add the counter. 
            Dim rateOfCounts64 As New CounterCreationData()
            rateOfCounts64.CounterType = PerformanceCounterType.RateOfCountsPerSecond64
            rateOfCounts64.CounterName = "RateOfCountsPerSecond64Sample"
            CCDC.Add(rateOfCounts64)

            ' Create the category.
            PerformanceCounterCategory.Create("RateOfCountsPerSecond64SampleCategory", _
            "Demonstrates usage of the RateOfCountsPerSecond64 performance counter type.", _
                PerformanceCounterCategoryType.SingleInstance, CCDC)
            Return True 
        Else
            Console.WriteLine("Category exists - RateOfCountsPerSecond64SampleCategory")
            Return False 
        End If 
    End Function 'SetupCategory


    Private Shared Sub CreateCounters()
        ' Create the counter.
        PC = New PerformanceCounter("RateOfCountsPerSecond64SampleCategory", "RateOfCountsPerSecond64Sample", False)

        PC.RawValue = 0
    End Sub 'CreateCounters


    Private Shared Sub CollectSamples(ByVal samplesList As ArrayList)

        Dim r As New Random(DateTime.Now.Millisecond)

        ' Initialize the performance counter.
        PC.NextSample()

        ' Loop for the samples. 
        Dim j As Integer 
        For j = 0 To 99

            Dim value As Integer = r.Next(1, 10)
            PC.IncrementBy(value)
            Console.Write((j.ToString() + " = " + value.ToString()))

            If j Mod 10 = 9 Then
                Console.WriteLine((";       NextValue() = " + PC.NextValue().ToString()))
                OutputSample(PC.NextSample())
                samplesList.Add(PC.NextSample())
            Else
                Console.WriteLine()
            End If
            System.Threading.Thread.Sleep(50)
        Next j
    End Sub 'CollectSamples


    Private Shared Sub CalculateResults(ByVal samplesList As ArrayList)
        Dim i As Integer 
        For i = 0 To (samplesList.Count - 1) - 1
            ' Output the sample.
            OutputSample(CType(samplesList(i), CounterSample))
            OutputSample(CType(samplesList((i + 1)), CounterSample))


            ' Use .NET to calculate the counter value.
            Console.WriteLine(".NET computed counter value = " + _
            CounterSampleCalculator.ComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())

            ' Calculate the counter value manually.
            Console.WriteLine("My computed counter value = " + _
            MyComputeCounterValue(CType(samplesList(i), CounterSample), CType(samplesList((i + 1)), CounterSample)).ToString())
        Next i
    End Sub 'CalculateResults




    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    '	PERF_COUNTER_COUNTER 
    '	Description	 - This counter type shows the average number of operations completed 
    '		during each second of the sample interval. Counters of this type 
    '		measure time in ticks of the system clock. The F variable represents 
    '		the number of ticks per second. The value of F is factored into the 
    '		equation so that the result can be displayed in seconds. 
    
    '	Generic type - Difference 
    
    '	Formula - (N1 - N0) / ( (D1 - D0) / F), where the numerator (N) represents the number 
    '		of operations performed during the last sample interval, the denominator 
    '		(D) represents the number of ticks elapsed during the last sample 
    '		interval, and F is the frequency of the ticks. 
    
    '	Average - (Nx - N0) / ((Dx - D0) / F)  
    
    '  Example - System\ File Read Operations/sec  
    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    Private Shared Function MyComputeCounterValue(ByVal s0 As CounterSample, ByVal s1 As CounterSample) As [Single]
        Dim numerator As [Single] = CType(s1.RawValue - s0.RawValue, [Single])
        Dim denomenator As [Single] = CType(s1.TimeStamp - s0.TimeStamp, [Single]) / CType(s1.SystemFrequency, [Single])
        Dim counterValue As [Single] = numerator / denomenator
        Return counterValue
    End Function 'MyComputeCounterValue


    Private Shared Sub OutputSample(ByVal s As CounterSample)
        Console.WriteLine(ControlChars.Lf + ControlChars.Cr + "+++++++++++")
        Console.WriteLine("Sample values - " + ControlChars.Lf + ControlChars.Cr)
        Console.WriteLine(("   BaseValue        = " + s.BaseValue.ToString()))
        Console.WriteLine(("   CounterFrequency = " + s.CounterFrequency.ToString()))
        Console.WriteLine(("   CounterTimeStamp = " + s.CounterTimeStamp.ToString()))
        Console.WriteLine(("   CounterType      = " + s.CounterType.ToString()))
        Console.WriteLine(("   RawValue         = " + s.RawValue.ToString()))
        Console.WriteLine(("   SystemFrequency  = " + s.SystemFrequency.ToString()))
        Console.WriteLine(("   TimeStamp        = " + s.TimeStamp.ToString()))
        Console.WriteLine(("   TimeStamp100nSec = " + s.TimeStamp100nSec.ToString()))
        Console.WriteLine("++++++++++++++++++++++")
    End Sub 'OutputSample
End Class 'App

RawFraction

Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Diagnostics

 _


Public Class App
    Private Shared PC As PerformanceCounter
    Private Shared BPC As PerformanceCounter


    Public Shared Sub Main()
        Dim samplesList As New ArrayList()

        'If the category does not exist, create the category and exit. 
        'Performance counters should not be created and immediately used. 
        'There is a latency time to enable the counters, they should be created 
        'prior to executing the application that uses the counters. 
        'Execute this sample a second time to use the counters. 
        If Not (SetupCategory()) Then
            CreateCounters()
            CollectSamples(samplesList)
            CalculateResults(samplesList)
        End If 

    End Sub 'Main


    Private Shared Function SetupCategory() As Boolean 


        If Not PerformanceCounterCategory.Exists("RawFractionSampleCategory") Then 


            Dim CCDC As New CounterCreationDataCollection()

            ' Add the counter. 
            Dim rf As New CounterCreationData()
            rf.CounterType = PerformanceCounterType.RawFraction
            rf.CounterName = "RawFractionSample"
            CCDC.Add(rf)

            ' Add the base counter. 
            Dim rfBase As New CounterCreationData()
            rfBase.CounterType = PerformanceCounterType.RawBase
            rfBase.CounterName = "RawFractionSampleBase"
            CCDC.Add(rfBase)

            ' Create the category.
            PerformanceCounterCategory.Create("RawFractionSampleCategory", _
            "Demonstrates usage of the RawFraction performance counter type.", _
                PerformanceCounterCategoryType.SingleInstance, CCDC)

            Return True 
        Else
            Console.WriteLine("Category exists - RawFractionSampleCategory")
            Return False 
        End If 
    End Function 'SetupCategory


    Private Shared Sub CreateCounters()
        ' Create the counters.
        PC = New PerformanceCounter("RawFractionSampleCategory", "RawFractionSample", False)

        BPC = New PerformanceCounter("RawFractionSampleCategory", "RawFractionSampleBase", False)

        PC.RawValue = 0
        BPC.RawValue = 0
    End Sub 'CreateCounters


    Private Shared Sub CollectSamples(ByVal samplesList As ArrayList)

        Dim r As New Random(DateTime.Now.Millisecond)

        ' Initialize the performance counter.
        PC.NextSample()

        ' Loop for the samples. 
        Dim j As Integer 
        For j = 0 To 99
            Dim value As Integer = r.Next(1, 10)
            Console.Write((j.ToString() + " = " + value.ToString()))

            ' Increment the base every time, because the counter measures the number  
            ' of high hits (raw fraction value) against all the hits (base value).
            BPC.Increment()

            ' Get the % of samples that are 9 or 10 out of all the samples taken. 
            If value >= 9 Then
                PC.Increment()
            End If 
            ' Copy out the next value every ten times around the loop. 
            If j Mod 10 = 9 Then
                Console.WriteLine((";       NextValue() = " + PC.NextValue().ToString()))
                OutputSample(PC.NextSample())
                samplesList.Add(PC.NextSample())
            Else
                Console.WriteLine()
            End If
            System.Threading.Thread.Sleep(50)
        Next j
    End Sub 'CollectSamples



    Private Shared Sub CalculateResults(ByVal samplesList As ArrayList)
        Dim i As Integer 
        For i = 0 To samplesList.Count - 1
            ' Output the sample.
            OutputSample(CType(samplesList(i), CounterSample))

            ' Use .NET to calculate the counter value.
            Console.WriteLine(".NET computed counter value = " + CounterSampleCalculator.ComputeCounterValue(CType(samplesList(i), CounterSample)).ToString())

            ' Calculate the counter value manually.
            Console.WriteLine("My computed counter value = " + MyComputeCounterValue(CType(samplesList(i), CounterSample)).ToString())
        Next i
    End Sub 'CalculateResults


    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    ' Formula from MSDN - 
    '      Description - This counter type shows the ratio of a subset to its set as a percentage. 
    '			For example, it compares the number of bytes in use on a disk to the 
    '			total number of bytes on the disk. Counters of this type display the  
    '			current percentage only, not an average over time. 
    
    ' Generic type - Instantaneous, Percentage  
    '	    Formula - (N0 / D0), where D represents a measured attribute and N represents one 
    '			component of that attribute. 
    
    '		Average - SUM (N / D) /x  
    '		Example - Paging File\% Usage Peak 
    '++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    Private Shared Function MyComputeCounterValue(ByVal rfSample As CounterSample) As [Single]
        Dim numerator As [Single] = CType(rfSample.RawValue, [Single])
        Dim denomenator As [Single] = CType(rfSample.BaseValue, [Single])
        Dim counterValue As [Single] = numerator / denomenator * 100
        Return counterValue
    End Function 'MyComputeCounterValue


    ' Output information about the counter sample. 
    Private Shared Sub OutputSample(ByVal s As CounterSample)
        Console.WriteLine("+++++++++++")
        Console.WriteLine("Sample values - " + ControlChars.Lf + ControlChars.Cr)
        Console.WriteLine(("   BaseValue        = " + s.BaseValue.ToString()))
        Console.WriteLine(("   CounterFrequency = " + s.CounterFrequency.ToString()))
        Console.WriteLine(("   CounterTimeStamp = " + s.CounterTimeStamp.ToString()))
        Console.WriteLine(("   CounterType      = " + s.CounterType.ToString()))
        Console.WriteLine(("   RawValue         = " + s.RawValue.ToString()))
        Console.WriteLine(("   SystemFrequency  = " + s.SystemFrequency.ToString()))
        Console.WriteLine(("   TimeStamp        = " + s.TimeStamp.ToString()))
        Console.WriteLine(("   TimeStamp100nSec = " + s.TimeStamp100nSec.ToString()))
        Console.WriteLine("++++++++++++++++++++++")
    End Sub 'OutputSample
End Class 'App 

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
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