On Thu, 2003-08-28 at 11:47, Lennart Sorensen wrote:

...

Have you looked at top while running dd with gzip? Might be CPU limited.

Lennart Sorensen

With gzip set anywhere between -2 and -7 I seem to get around 15-25% idle time, which seems to indicate that there's enough processor time. It does bounce around a lot though, anywhere between 97% to 60% use for gzip.

I would suspect (with almost no evidence) that you may be missing latency windows (especially on write). It would not take too many times for the disk to have to spin (almost) all the way round to hammer the total transfer rate pretty good. If you could get more buffers in the pipe that might help. Jim -- The Toronto Linux Users Group. Meetings: http://tlug.ss.org TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://tlug.ss.org/subscribe.shtml