Date: Fri, 27 Nov 1998 01:20:35 -0600 (CST) From: Chris Dillon <cdillon@wolves.k12.mo.us> To: Stormy Henderson <stormy@futuresouth.com> Cc: questions@FreeBSD.ORG Subject: Re: Slow CCD Message-ID: <Pine.BSF.4.05.9811270012130.15006-100000@duey.hs.wolves.k12.mo.us> In-Reply-To: <199811270320.VAA23941@shell.futuresouth.com>
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On Thu, 26 Nov 1998, Stormy Henderson wrote:
> I have an Adaptec 2940 with 2 matched 1GB SCSI-2 drives, 5400rpm, 10ms access.
> Using dd bs=1m count=128 if=/dev/da0s1e of=/dev/null, I get 4MB per second,
> and about the same with 8k blocks. Using CCD with an interleave of 512, and
> the same dd, I get 1MB per second. Increasing the interleave to 65535 improves
> performance to a miserable 1.7MB per second. Forgetting interleave and just
> concatting them doesn't do any better.
>
> I have a p133, by the way.
>
> Is the abysmal performance normal on my hardware? I'm using 3.0-19981123-SNAP.
>
Hmm, you sparked my interest, so I did some tests on my own box.
Luckily I kept the benchmarks I did from a while ago.
I have two IBM 4.3GB 5200RPM 10ms drives on a NCR 53c875.
I tested this with bonnie using a CCD stripe size of 64.
Unfortunately, the lines are wrapped, but hopefully you can make sense
of it.
-------Sequential Output-------- ---Sequential Input--
--Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block---
--Seeks---
When I ran 2.2-stable, circa 2.2.6:
500 5181 97.9 12668 54.2 3545 22.0 5926 97.9 14646 44.5
86.5 3.5
3.0, pre-CAM (notice I only used a 200MB testfile this time.. oops):
200 5094 98.5 11889 54.5 2854 24.1 5234 96.1 8079 35.0
157.4 6.2
3.0 as of very recently:
500 5518 94.7 5479 37.2 2540 20.0 6204 93.6 12245 56.0
111.4 7.2
Hard to say if the interesting differences are because of CAM or other
changes that have been made.
-- Chris Dillon - cdillon@wolves.k12.mo.us - cdillon@inter-linc.net
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