Question

Does System.Diagnostics.Stopwatch count time during computer stand by?

Answer 1

Yes it does.

Looking at the code in Reflector shows that if it is not Stopwatch.IsHighResolution, then it will use the tick count (in my environment, the value was false so it will use DateTime.UtcNow.Ticks):

public void Start()
{
    if (!this.isRunning)
    {
        this.startTimeStamp = GetTimestamp();
        this.isRunning = true;
    }
}



public static long GetTimestamp()
{
    if (IsHighResolution)
    {
        long num = 0L;
        SafeNativeMethods.QueryPerformanceCounter(out num);
        return num;
    }
    return DateTime.UtcNow.Ticks;
}