I am using a Cypress FX2, and the fastest bulk speed I can get in Linux is 30MB/s. If I include writing the data to disk that speed is 15MB/s. I see that CPU use is at 100% when doing these transactions.
Getting 30MB/s requires very specific conditions: 0x1000 size user read buffer 0x1000 size URB buffer With libusb I only get 16MB/s. Is there a libusb implementation for ISO planned? I am interested in techniques people have found (for example should I malloc a full 4k page for the URB? Use bulk queueing [I could not get this to work in 2.4.21] What other techniques have been found to increase speed?) Have any other driver developers seen faster speeds? Can Linux write to disk in iso at 24MB/s? Is this a hardware problem that we do not get 60MB/s (or 52MB/s)? Hopefully, this will be solved in the future. I am going to test bulk transfers on XP and I will report the results. According to one Cypress document the FX2 averages 39MB/s in XP (so 9MB/s faster than I am getting on Linux, but still under the 50MB/s claim). The important thing for me is that I can write to disk using iso at 24MB/s. Ted -- Ted Huntington Programmer Analyst I Main Library University of California, Irvine PO Box 19557 Irvine, CA 92623-9557 emesgs: [EMAIL PROTECTED] web page: http://business.lib.uci.edu/webpages/ted.htm 8:00a-12:00p Business Office (949) 824-8926 1:00p-5:00p Multimedia Resource Center (949) 824-1674 "Stop violence, teach science." ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
