Question

I am playing around with C# collections and I have decided to write a quick test to measure the performance of different collections.

My performance test goes like this:

int numOps= (put number here);
long start, end, numTicks1, numTicks2;
float ratio;

start = DateTime.Now.Ticks;

for(int i = 0; i < numOps; i++)
{
  //add two elements to collection #1
  //remove one element from collection #1
}

end = DateTime.Now.Ticks;

numTicks1 = end - start;


start = DateTime.Now.Ticks;

for(int i = 0; i < numOps; i++)
{
  //add two elements to collection #2
  //remove one element from collection #2
}

end = DateTime.Now.Ticks;

numTicks2 = end - start;

ratio = (float)numTicks2/(float)numTicks1;

Then I compare the ratio value using different Collections and different values for numOps to see how they compare.

The problem is sometimes when I use a small enough number (numOps = 500), the test results between a Hashtable and List are sporadic (in other words it’s a coin flip which one is faster). Can anyone explain why this is?

EDIT: Thanks everyone! Stopwatch works like a charm.

Answer 1

try taking a look at StopWatch class instead of using DateTime

this example straight out of MSDN

    Stopwatch stopWatch = new Stopwatch();
    stopWatch.Start();
    Thread.Sleep(10000); //your for loop
    stopWatch.Stop();
    // Get the elapsed time as a TimeSpan value.
    TimeSpan ts = stopWatch.Elapsed;

    // Format and display the TimeSpan value.
    string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
        ts.Hours, ts.Minutes, ts.Seconds,
        ts.Milliseconds / 10);
    Console.WriteLine(elapsedTime, "RunTime");