On Tue, Jun 24, 2008 at 11:11 PM, Nick Rout <[EMAIL PROTECTED]> wrote: > I have an imation 4G flash drive that is sitting in a USB2 port. I am > transferring a 3.7G file from the computers sata hard drive to the usb > drive. > > It seems to be taking about 20 minutes This seems far too long. USB > data rate 60MB/s. > > 3719MB/60MB/s = 62 seconds, give or take. > > Now I know I won't get a sustained rate anywhere near that, but the > predicted time is 20 odd times over the theoretical minimum time. > > So where should I look for problems. Suspicions centre around: > > 1. USB flash drive cannot handle the data rate, tough one Nick; or > > 2. USB operating at USB1.1 rate only. How would I diagnose that? > > Its an intel based compaq motherboard, excerpts from lspci: > > 00:1d.0 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB > UHCI Controller #1 (rev 02) > 00:1d.1 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB > UHCI Controller #2 (rev 02) > 00:1d.2 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB > UHCI Controller #3 (rev 02) > 00:1d.7 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB2 > EHCI Controller (rev 02) > > dmesg displays a lot of lines with the term USB in them, dunno whats relevant. >
Further to that it is transferring to my other computer at 13MB/s, whereas the first one went at only 2.5MB/s. Is the difference that you can read from flash disk 6 times faster than you can write to it? (thats a guess, not a statement of fact).
