c# Array copying performance test

ArrayCopyPerformanceTest.cs

// from https://stackoverflow.com/questions/30636113/get-subarray-of-byte/30636227#30636227
// added Buffer.Copy() test
// added ArraySegment().ToArray() test

public static void Test()
{
  const int MAX = 1000000;

  int[] arrByte1 = Enumerable.Range(0, 1000).ToArray();
  int[] arrByte2 = new int[500];
  Stopwatch sw = new Stopwatch();

  // Array.Copy
  sw.Start();
  for (int i = 0; i < MAX; i++)
  {
    Array.Copy(arrByte1, 500, arrByte2, 0, 500);
  }
  sw.Stop();
  Console.WriteLine("Array.Copy: {0}ms", sw.ElapsedMilliseconds);

  // Linq
  sw.Restart();
  for (int i = 0; i < MAX; i++)
  {
    arrByte2 = arrByte1.Skip(500).Take(500).ToArray();
  }
  sw.Stop();
  Console.WriteLine("Linq: {0}ms", sw.ElapsedMilliseconds);

  // Buffer.BlockCopy
  sw.Restart();
  for (int i = 0; i < MAX; i++)
  {
    Buffer.BlockCopy(arrByte1, 500, arrByte2, 0, 500);
  }
  sw.Stop();
  Console.WriteLine("Buffer.BlockCopy: {0}ms", sw.ElapsedMilliseconds);
  
  // ArraySegment
  sw.Restart();
  for (int i = 0; i < MAX; i++)
  {
    arrByte2 = new ArraySegment<int>(arrByte1, 500, 500).ToArray();
  }
  sw.Stop();
  Console.WriteLine("ArraySegment: {0}ms", sw.ElapsedMilliseconds);

}

Typical results on W10 VMWare:

• Array.Copy: 360ms
• Linq: 31335ms
• Buffer.BlockCopy: 84ms
• ArraySegment: 600ms