On Thu, 2007-05-31 at 09:38 -0400, Lennart Sorensen wrote: > On Thu, May 31, 2007 at 11:23:03AM +0200, David Fokkema wrote: > > I know. However, it would be nice to get around 30 Mb/s, which is less > > than 10% of it. When I 'dd', I get around 7 Mb/s with CPU at ~ 80% which > > is almost entirely spent as 'system'. I used: > > > > dd if=/dev/zero of=test.bin bs=1024 count=102400 > > > > (I just did the test) > > > > Do you see the same figures? Why is so much time spent as 'system'? I > > would've understood if it was 'wait' or something like that... Don't we > > have DMA? > > Remember USB is measured in bits per second not bytes per second, so > 480Mbit/s generally only gets about 22MB/s even on a very high end PC due > to whatever overhead is involved in USB. Firewire seems to be able to > get much closer to its theoretical limits while using a lot less CPU > too.
Ouch! I'll grab my disk and check its speed on my 'high-end' laptop to see what it gives me. Thanks, David -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
