On Tuesday 05 December 2006 4:11 am, David Relson wrote: > Good info. So 28 is achievable and 33 is out of reach.
For mass storage devices, I've never seen 33. I've seen a bit over 30; the primary bottleneck seems to be inside the mass-storage device, rather than on the host side. > Stated differently, USB 2.0 has a theoretical max of 480Mbps, which is > 60 MB/sec, but in actual practice only about 50% of that is attainable. The most I've ever seen streamed -- between a fast host and an FX2 eight-bit microcontroller doing exactly nothing with that data -- is just shy of 50 MB/sec. Which using Alan's numbers means it all but saturated the available bulk bandwidth. Which is further evidence that the bottleneck is either in the mass storage protocol (it has no pipelining) or in the peripheral silicon ... since the disks themselves are often capable of more than 50 MB/sec. - Dave ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
