Date: Wed, 14 Jan 2004 23:21:00 +1000 From: Mark Sergeant <msergeant@snsonline.net> To: Ari Suutari <ari@suutari.iki.fi> Cc: freebsd-stable@freebsd.org Subject: Re: Adaptect raid performance with FreeBSD Message-ID: <1074086459.2080.0.camel@localhost> In-Reply-To: <200401141453.50150.ari@suutari.iki.fi> References: <200401141453.50150.ari@suutari.iki.fi>
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--=-M0KZ1fMW41g2riYrDxXD Content-Type: text/plain Content-Transfer-Encoding: quoted-printable I've got to say this seems pretty bad since my laptop gets ... 104857600 bytes transferred in 4.491311 secs (23346770 bytes/sec) On Wed, 2004-01-14 at 22:53, Ari Suutari wrote: > Hi, >=20 > I have been wondering if my disk setup should perform better than > it is now doing.=20 >=20 > I have a dual PIII 500 Mhz with intel server mother board. > (a couple of years old). On that, I have DPT (or currently Adaptec) > raid controller "DPT PM2654U2", which supports 40 Mhz SCSI bus, > giving a theoretical data transfer speed of 80 MB/s. There are > two physical disks, which have been mirrored (ie. raid-1). > The disks are maxtor atlas 10K4, I think that maxtor tells > that they should give sustained transfer rate up to 72MB/s. > I have confirmed that SCSI bus is at 80MB/s speed > with dptutil. >=20 > The system is running FreeBSD 4.8. >=20 > However, when reading raw device with dd like this: >=20 > dd if=3D/dev/rda1s1a of=3D/dev/null bs=3D1m count=3D100 > 100+0 records in > 100+0 records out > 104857600 bytes transferred in 4.193832 secs (25002814 bytes/sec) >=20 > So, I get only about 25MB/s. Shouldn't I be getting something > like 70 MB/s, or even more since there are two disks that > can server read requests ? >=20 > Maybe there is something I could tune ? The BIOS doesn't > have much, there is only setting to enable bus mastering (enabled) > and another for pci latency timer values (was 40, I think) >=20 >=20 > Ari S. --=20 Mark Sergeant <msergeant@snsonline.net> SNSOnline Technical Services --=-M0KZ1fMW41g2riYrDxXD Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQBABUI7bS4ZEpHb8t0RApAzAJ0aiaUmZHW3jzBoYvM0zfZSQgWusACdG+qV hudbg/dC+7P1QonvoJGcomE= =pHSU -----END PGP SIGNATURE----- --=-M0KZ1fMW41g2riYrDxXD--
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