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Subject: Re: SCSI, U2W in particular?, and poor performance...
From: Wietse Venema (wietseporcupine.org)
Date: Sat Mar 04 2000 - 21:22:23 CST

Um, what SOFTWARE was runing on these boxen? There are
significant differences in speed and reliability.

        Wietse

Justin Robertson:
>
> Using fsstone and smtpstone, I've noticed some 'quirks' in performance.
> For example, on an extremely low end Celeron 400 with 32MB of ram and a
> cheap 6.4gig IDE HD, I can succesfully create/delete 1024 files using
> fsstone in about 2 seconds. Using smtp-source I can send 1000 15k messages
> in 44 seconds, using only 2% of the CPU. Now, this is good, however, when
> the same tests are attempted on a conciderably higher end box, 800MHz,
> 768MB of RAM, and 10,000rpm 18.2gig U2W SCSI HDs, the results are... well,
> far lower then the low end machine. It takes 14 seconds to perform the
> same fsstone test, and well over 7 minutes to perform the same
> smtp-source test. Perplexed I attempted a series of CPU and HD tests on
> the high end machine, and it was performing as would be expected. Is there
> something about the way that postfix reads/writes data that is 'iffy' in
> the SCSI drivers at this point? This would make no sense to me... I've
> check with another individual whom is using a different SCSI controller
> card, ncr xxx vs. my adaptec a2940u2w, and the results are comprable. What
> gives? Anybody have an idea? I could just put everything on to a RAM disk,
> but the point is that a crappy machine shoudln't be smoking the highend
> box.
>
>
> Justin Robertson
> <zululinux.com>
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