This combination is WRONG because
Stopwatch stopWatch = new Stopwatch(); stopWatch.Start(); //starts test test_cnt = 0; total_cnt = 0; for (int i = 0; i < packets; i++) { SendFPGAcommand(ref TE_USB_FX2_USBDevice, MB_Commands.FX22MB_REG0_START_TX, TIMEOUT_MS); packetlen = PACKETLENGTH; TE_USB_FX2.TE_USB_FX2.TE_USB_FX2_SetData(ref TE_USB_FX2_USBDevice, ref buffer, ref packetlen, PI_EP6, TIMEOUT_MS,BUFFER_SIZE); Buffer.BlockCopy(buffer,0, data, total_cnt, packetlen); total_cnt += packetlen; SendFPGAcommand(ref TE_USB_FX2_USBDevice, MB_Commands.FX22MB_REG0_STOP, TIMEOUT_MS); } stopWatch.Stop(); TimeSpan ts = stopWatch.Elapsed;