Stopwatch.Frequency Field (System.Diagnostics)

Frequency Field

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

Stopwatch..::.Frequency Field

Gets the frequency of the timer as the number of ticks per second. This field is read-only.

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

Syntax

Visual Basic (Declaration)

Public Shared ReadOnly Frequency As Long

Visual Basic (Usage)

Dim value As Long

value = Stopwatch.Frequency

public static readonly long Frequency

Visual C++

public:
static initonly long long Frequency

JScript

public static final var Frequency : long

Remarks

The timer frequency indicates the timer precision and resolution. For example, a timer frequency of 2 million ticks per second equals a timer resolution of 500 nanoseconds per tick. In other words, because one second equals 1 billion nanoseconds, a timer frequency of 2 million ticks per second is equivalent to 2 million ticks per 1 billion nanoseconds, which can be further simplified to 1 tick per 500 nanoseconds.

The Frequency value depends on the resolution of the underlying timing mechanism. If the installed hardware and operating system support a high-resolution performance counter, then the Frequency value reflects the frequency of that counter. Otherwise, the Frequency value is based on the system timer frequency.

Because the Stopwatch frequency depends on the installed hardware and operating system, the Frequency value remains constant while the system is running.

Examples

The following example displays the frequency and resolution of a Stopwatch timer. This code example is part of a larger example provided for the Stopwatch class.

Visual Basic

Public Shared Sub DisplayTimerProperties()

   ' Display the timer frequency and resolution.
   If Stopwatch.IsHighResolution Then
      Console.WriteLine("Operations timed using the system's high-resolution performance counter.")
   Else
      Console.WriteLine("Operations timed using the DateTime class.")
   End If

   Dim frequency As Long = Stopwatch.Frequency
   Console.WriteLine("  Timer frequency in ticks per second = {0}", frequency)
   Dim nanosecPerTick As Long = 1000000000 / frequency
   Console.WriteLine("  Timer is accurate within {0} nanoseconds", nanosecPerTick)

End Sub

public static void DisplayTimerProperties()
{
    // Display the timer frequency and resolution.
    if (Stopwatch.IsHighResolution)
    {
        Console.WriteLine("Operations timed using the system's high-resolution performance counter.");
    }
    else 
    {
        Console.WriteLine("Operations timed using the DateTime class.");
    }

    long frequency = Stopwatch.Frequency;
    Console.WriteLine("  Timer frequency in ticks per second = {0}",
        frequency);
    long nanosecPerTick = (1000L*1000L*1000L) / frequency;
    Console.WriteLine("  Timer is accurate within {0} nanoseconds", 
        nanosecPerTick);
}

Visual C++

void DisplayTimerProperties()
{
   // Display the timer frequency and resolution.
   if ( Stopwatch::IsHighResolution )
   {
      Console::WriteLine( "Operations timed using the system's high-resolution performance counter." );
   }
   else
   {
      Console::WriteLine( "Operations timed using the DateTime class." );
   }

   Int64 frequency = Stopwatch::Frequency;
   Console::WriteLine( "  Timer frequency in ticks per second = {0}", frequency );
   Int64 nanosecPerTick = (1000L * 1000L * 1000L) / frequency;
   Console::WriteLine( "  Timer is accurate within {0} nanoseconds", nanosecPerTick );
}

public static void DisplayTimerProperties()
{
    // Display the timer frequency and resolution.
    if (Stopwatch.IsHighResolution) {
        Console.WriteLine("Operations timed using the system's "
            + "high-resolution performance counter.");
    }
    else {
        Console.WriteLine("Operations timed using the DateTime class.");
    }

    long frequency = Stopwatch.Frequency;
    Console.WriteLine("  Timer frequency in ticks per second = {0}", 
        (Int64)frequency);
    long nanoSecPerTick = (1000L * 1000L * 1000L) / frequency;
    Console.WriteLine("  Timer is accurate within {0} nanoseconds", 
        (Int64)nanoSecPerTick);
} //DisplayTimerProperties

Platforms

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360

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.

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