CopyTo performance about ilgpu HOT 3 CLOSED

using System;
using System.Diagnostics;
using System.Linq;
using ILGPU;
using ILGPU.Runtime;

namespace ilgpuTest
{
  class Program
  {
    private static Action<Index, int, int, int, ArrayView<byte>, ArrayView<byte>> _kernel;

    static void Main(string[] args)
    {
      var width = 3840;
      var height = 2160;
      var bytesPerPixel = 3;
      var pixels = width * height;
      var length = width * height * bytesPerPixel;
      var buffer = CreateBuffer(width, height, bytesPerPixel);
      var buffer2 = new byte[length];

      using (var context = new Context())
      {
        var cudaId = Accelerator.Accelerators.First(a => a.AcceleratorType.Equals(AcceleratorType.Cuda));
        using (var accelerator = Accelerator.Create(context, cudaId))
        {
          for (int x = 0; x < 10; x++)
          {
            _kernel = accelerator.LoadAutoGroupedStreamKernel<Index, int, int, int, ArrayView<byte>, ArrayView<byte>>(KernelMethod);
            var inputBuffer = accelerator.Allocate<byte>(length);
            var ouputBuffer = accelerator.Allocate<byte>(length);

            var swFrom = Stopwatch.StartNew();
            inputBuffer.CopyFrom(buffer, 0, 0, length);
            swFrom.Stop();
            Console.WriteLine($"{x} - CopyFrom: {swFrom.ElapsedMilliseconds}");
            _kernel(pixels, width, height, bytesPerPixel, inputBuffer.View, ouputBuffer.View);
            accelerator.Synchronize();
            var result = new byte[length];
            var swCopy = Stopwatch.StartNew();
            ouputBuffer.CopyTo(result, 0, 0, length);
            // ouputBuffer.CopyTo(buffer2, 0, 0, length); // Use this to increase the speed (only first run will be slow).
            swCopy.Stop();
            Console.WriteLine($"{x} - CopyTo: {swCopy.ElapsedMilliseconds}");
          }
        }
      }
    }

    private static void KernelMethod(Index pixelIndex, int width, int height, int bpp, ArrayView<byte> source, ArrayView<byte> destination)
    {
      var offset = width * height;
      var r = source[pixelIndex];
      var g = source[pixelIndex + offset];
      var b = source[pixelIndex + offset * 2];

      destination[pixelIndex * bpp] = b;
      destination[pixelIndex * bpp + 1] = g;
      destination[pixelIndex * bpp + 2] = r;
    }

    private static byte[] CreateBuffer(int width, int height, int bytesPerPixel)
    {
      var length = width * height * bytesPerPixel;
      var result = new byte[length];

      byte c = 0;
      for (var p = 0; p < length; p++)
      {
        result[p] = c++;
      }

      return result;
    }
  }
}