USB Transfer Performance RRS feed

  • Question

  • I've been developing some USB drivers for real-time data acquisition and have noticed what seems to be a performance limitation of 14-15 Mb/s on several, modern, CE systems. Is there something limiting the USB bandwidth on CE systems? I've seen this performance both with my drivers as well as mass storage devices (like flash drives). Both are capable of more than 10x that performance on a standard desktop configuration. And, yes, all my systems report that the USB port is high-speed.


    Wednesday, May 19, 2010 1:50 PM

All replies

  • On which kind of devices are you seeing this speed limitation? Are you connecting multiple devices to the same USB controller?

    If you are working on an x86 platform you can compare those performances with the ones you get from a Windows XP/Vista/7 installation on the same hardware.

    The 480Mb/s maximum speed will be difficult to reach on ARMs or other platform with low clock speeds and low memory.

    If you think that you hardware is powerful enough to handle higher transfer speeds, check that your current USB host driver uses DMA (if available) and, if your processor supports some kind of arbitration on the internal bus, check that USB host has an high priority on the bus.

    Valter Minute
    Windows Embedded MVP
    Friday, May 21, 2010 11:16 AM