On Thu, 24 Oct 2002, David Brownell wrote: > And performance information too. I noticed that running full > speed bulk traffic through a USB 2.0 hub is about 25% slower > than running it through a full/low speed host controller, at > least for higher volumes,
Unfortunately, when running over HS/TT hub, I didn't manage to get any of the sg_list testcases 5-8 working without getting stuck in D-state sooner or later. I had a few occasions where test5 didn't get stuck and then it was completed (default test parameters) in 17.5 sec. This compares to the 17.0 sec it needs on the same port (NEC) without HS/TT, i.e. with companion ohci - no matter with or without hub running at FS in between. On an USB-1.1 ohci port (SiS-7001) it takes 16.0 sec for the same test. > but the latency for short requests > is much reduced (they can complete before the next SOF). Yep. Testcases 1-4 suggest with HS/TT hub the transfers are completed taking 5 microframes (-s 512) or even as little as 1 microframe (-s 64). Martin ------------------------------------------------------- This SF.net email is sponsored by: ApacheCon, November 18-21 in Las Vegas (supported by COMDEX), the only Apache event to be fully supported by the ASF. http://www.apachecon.com _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
