On Tue, 18 Jan 2005, John H. wrote: > time dd if=/dev/sdg1 of=/tmp/bigFile bs=1M count=100 > 100+0 records in > 100+0 records out > > real 0m48.328s > user 0m0.000s > sys 0m1.412s
Transferring 100 MB in about 50 seconds is around 2 MB/s. That's definitely lower than you want to see in a high-speed device; it should be closer to 30 MB/s or even more. On the other hand, it's faster than a full-speed transfer can possibly go: Even if all the bits were used for data (which they aren't) you wouldn't get any more than 1.5 MB/s -- 800 KB/s is more typical. It's not clear what the cause of your slowdown could be. The best suggestion I can offer at this point is that you rebuild the usb-storage driver after turning on the usb-storage verbose debugging option in the kernel configuration. Make sure your /etc/syslog.conf is set to capture kernel debug-level messages somewhere and run the test over again. The mesages in the log may indicate a trouble spot. Alan Stern ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ Linux-usb-users@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
