From: Brad Campbell <brad@wasp.net.au>
To: linux-ide@vger.kernel.org
Subject: sata_promise performance observations
Date: Sat, 23 Oct 2004 12:36:54 +0400 [thread overview]
Message-ID: <417A1826.5010502@wasp.net.au> (raw)
G'day all,
Interesting observation with 3 SATA150TX4 cards and 10 Maxtor Maxline-II 250GB SATA drives.
If I run a concurrent dd if=/dev/sda > /dev/null and dd if=/dev/sdb > /dev/null I get the expected
115MB/s transfer rates in vmstat.
If I do a dd if=/dev/sda > /dev/null and dd if=/dev/sde > /dev/null I get about 80MB/s
sda, sde & sdi I get
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
3 0 22540 2560 463908 5320 0 0 85294 16 1102 761 11 88 0 1
3 1 22540 1480 464852 5320 0 0 86493 25 987 512 13 86 0 0
2 2 22540 2176 464304 5268 0 0 86774 18 1091 721 12 87 0 1
2 2 22540 1488 464860 5368 0 0 85562 18 921 416 13 87 0 0
When streaming from drives not on the same controller, I lose about 30mb/s transfer rate. In fact,
it seems to max out at about 86MB/s no matter what combination of drives I use if I stream from more
than one controller.
However, if I use sda, sbb & sdc I get
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
0 3 22512 1768 464448 5304 0 0 121661 18 1257 566 9 59 0 32
0 3 22512 1536 464696 5316 0 0 122903 14 1262 578 10 59 0 31
0 3 22512 2112 464228 5268 0 0 121655 14 1255 578 9 60 0 32
How bizzare. I have latency set to 32 on all controllers, but I have tried as low as 8 and as high
as 128 to no avail.
I have readahead set to 4096 on all devices.
Anyone have any ideas?
Not that this is an issue for me (I'm only using it as a fileserver over GB eth so its not like
100MB/s is actually required, just an interesting observation)
Regards,
Brad
next reply other threads:[~2004-10-23 8:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-23 8:36 Brad Campbell [this message]
2004-10-25 17:55 ` sata_promise performance observations Eric Mudama
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=417A1826.5010502@wasp.net.au \
--to=brad@wasp.net.au \
--cc=linux-ide@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).