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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)

public static readonly long Frequency

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.

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.

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.");
        Console.WriteLine("Operations timed using the DateTime class.");

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

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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