> It probably will be significantly less. We have buffer size issues with > usbfs and libusb. > > Older versions of libusb used the synchronous bulk read/write calls and > those were limited to a page size. We've since switched to using > asynchronous, URB based calls, which allow us buffer sizes of up to > 16KB, but I think that will still limit us to quite a bit under 30MB/s. > > We can go even further by using multiple URBs and queuing them, but > libusb doesn't currently do that.
Hi Johannes, maybe it should allocate multiple pages and then use scatter-gather io out of them. That avoids having to allocate large contiguous lumps of kernel memory, and should also be good for performance. Ciao, Duncan. ------------------------------------------------------- This Newsletter Sponsored by: Macrovision For reliable Linux application installations, use the industry's leading setup authoring tool, InstallShield X. Learn more and evaluate today. http://clk.atdmt.com/MSI/go/ins0030000001msi/direct/01/ _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
