But anyway, I really need to profile my code to see where the bottleneck is.

I've got a MiniMax, and transfering 700MB to RAM using Ambient copy, leads me to 21MB/s in best case. Using USB2.0 gives 23MB/s in best case.

Even if Ambient copy process sends SCSI requests with 256KB buffers, I've found this FW limitation strange. That's why I really need to profile my code.