C# outperforms vb og c++

Jeg har noget kode som jeg gerne vil portere til VB og c++. Ikke desto mindre finder jeg eksekverings hastigheden i VB og c++ rystende langsom i forhold til c#. Er der nogen der kan forklare om jeg kan optimere mit VB kode... og mit c++ u/pointere kode. Her er tiderne:

1) c#: 0.3 sec
2) c++ u/pointere: 1.4 sec
3) c++ m/pointere: 0.015 sec
4) VB: 25 sec

Koden er som foelger:
1) c#:
int count = 1024 * 3 * 768;

byte[] bs = new byte[count];

DateTime start = DateTime.Now;

for (int h = 0; h < 100; h += 3)
{
  for (int i = 0; i < count - 1; i += 3)
  {
    byte r = bs[i + 2];
    byte g = bs[i + 1];
    byte b = bs[i + 0];

    bs[i + 0] = (byte)(255 - b);
    bs[i + 1] = (byte)(255 - r);
    bs[i + 2] = (byte)(255 - g);
  }
}

DateTime end = DateTime.Now;

MessageBox.Show((end - start).ToString());

2) c++ u/pointere:
int byteWidth = 1024 * 3;
int byteHeight = 768;
int count = byteWidth * byteHeight;

DWORD start = GetTickCount();

char* bs = new char[count];

for(int h = 0; h <100; h++)
{
  for(int i = 0; i < count - 1; i+=3)
  {
    char r = bs[i + 2];
    char g = bs[i + 1];
    char b = bs[i + 0];

    bs[i + 0] = (char)(255 - b);
    bs[i + 1] = (char)(255 - r);
    bs[i + 2] = (char)(255 - g);
  }
}

DWORD end = GetTickCount();

DWORD interval = end - start;

printf ("Width trick: %d \n", interval);

3) c++ m/pointere:
int byteWidth = 1024 * 3;
int byteHeight = 768;
int count = byteWidth * byteHeight;

DWORD end = GetTickCount();

DWORD interval = end - start;

int index = 0;

while(index < count)
{
  char r = *(bs + index + 2);
  char g = *(bs + index + 1);
  char b = *(bs + index + 0);

  *(bs + index + 0) = 255 - b;
  *(bs + index + 1) = 255 - g;
  *(bs + index + 2) = 255 - r;
  index+=3;
}

DWORD end2 = GetTickCount();

DWORD interval2 = end2 - end;

printf ("Width trick: %d \n", interval2);

4) VB:
Dim count As Long
count = 1024 * 3
count = count * 768

Dim bs2() As Byte

ReDim Preserve bs2(count)

Dim r As Byte
Dim g As Byte
Dim b As Byte
Dim lngStart As Long
Dim lngFinish As Long

lngStart = GetTickCount()

For h = 0 To 100
    For i = 0 To count - 1 Step 3
        r = bs2(i + 0)
        g = bs2(i + 1)
        b = bs2(i + 2)
       
        bs2(i + 0) = 255 - r
        bs2(i + 1) = 255 - g
        bs2(i + 2) = 255 - b
    Next
Next

lngFinish = GetTickCount()

MsgBox CStr(lngFinish - lngStart)