BitBlt slooooow as hell

[Vegeta]

I used this code to capture the entire screen and to write the bitmap into an array:

Dim bBytes(1 To 2359296) As Byte
    Dim hdc0 As Long
    Dim idc As Long
    Dim ibitmap As Long
    
    With bi24BitInfo.bmiHeader
        .biBitCount = 24
        .biCompression = BI_RGB
        .biPlanes = 1
        .biSize = Len(bi24BitInfo.bmiHeader)
        .biWidth = 1024
        .biHeight = 768
    End With
 
    hdc0 = GetDC(0)
    idc = CreateCompatibleDC(0)
 
    ibitmap = CreateDIBSection(idc, bi24BitInfo, DIB_RGB_COLORS, ByVal 0&, ByVal 0&, ByVal 0&)
    
    SelectObject idc, ibitmap
    BitBlt idc, 0, 0, bi24BitInfo.bmiHeader.biWidth, bi24BitInfo.bmiHeader.biHeight, hdc0, 0, 0, vbSrcCopy
    GetDIBits hdc0, ibitmap, 0, bi24BitInfo.bmiHeader.biHeight, bBytes(1), bi24BitInfo, DIB_RGB_COLORS

it took ~ 500 ms to perform this code as compiled application.
i found out that the line with the bitblt call takes ~ 460ms.
but why so long? this command only copies 2,3 MB from one memory block to the other.... that cant take 500 ms...
how can I optimate this line of code?

thanks for any help