Date: Wed, 20 Oct 2004 04:09:08 +0800 From: Xin LI <delphij@frontfree.net> To: Mike Jakubik <mikej@rogers.com> Cc: freebsd-current@freebsd.org Subject: Re: FreeBSD 5.3b7and poor ata performance Message-ID: <20041019200908.GA655@frontfree.net> In-Reply-To: <4129.192.168.0.188.1098211592.squirrel@192.168.0.188> References: <20041015190638.C5A0E5D04@ptavv.es.net> <41715E7F.7060509@ng.fadesa.es> <20041018100045.f8koww0skcco0woo@www.sweetdreamsracing.biz> <4173D66F.6010200@DeepCore.dk> <4173F2E9.7010407@ng.fadesa.es> <417406E3.9010706@DeepCore.dk> <4174FD04.8040000@ng.fadesa.es> <20041019104525.ikgw8kcw8sw480os@www.sweetdreamsracing.biz> <4129.192.168.0.188.1098211592.squirrel@192.168.0.188>
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--OXfL5xGRrasGEqWY Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, Mike, On Tue, Oct 19, 2004 at 02:46:32PM -0400, Mike Jakubik wrote: > Out of curiosity, i ran this on one of our production servers, which runs > on a dual Xeon MB, with SCSI raid-10 setup, and to my surprise here are > the results: >=20 > CPU: Intel(R) Xeon(TM) CPU 2.80GHz (2799.22-MHz 686-class CPU) > real memory =3D 2146959360 (2047 MB) > avail memory =3D 2099650560 (2002 MB) > FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs >=20 > da0 at asr0 bus 0 target 0 lun 0 > da0: <ADAPTEC RAID-10 3B0A> Fixed Direct Access SCSI-2 device >=20 > FreeBSD 5.3-BETA4 #0: Sun Sep 12 13:09:43 EDT 2004 >=20 > (Custom kernel, no debugging) >=20 > # dd if=3D/dev/da0 of=3D/dev/null bs=3D1m count=3D200 > 200+0 records in > 200+0 records out > 209715200 bytes transferred in 6.225309 secs (33687517 bytes/sec) >=20 > Why is a SCSI raid-10 system slower than a plain IDE disk? Something is > wrong here. Unfortunatelly I can reproduce similiar problem when using Ultra320 under mpt(4) and a version of Adaptec's SCSI card (maybe aic, or something else, which I have to go to my office to find out). Additionally the problem is not FreeBSD specific, with a Linux installation, it shows poor performance too. (No RAID configuration, though). I found that block size does influence performance greatly. With a block size of 131072 I got peak read performance at about 70MB/s, but that's all. I did not have the necessary knowledge at the time I have did the test last month, so I got only the result and thought that I have made something wrong and hoped someone to correct me with no luck :-( Cheers, --=20 Xin LI <delphij frontfree net> http://www.delphij.net/ See complete headers for GPG key and other information. --OXfL5xGRrasGEqWY Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (FreeBSD) iD8DBQFBdXRk/cVsHxFZiIoRAvwOAJ0REPVNYi0evM8ZxiVLkGNThQAEWwCbBXUm W9YqFlA/+oBZt9bWBwsW8rk= =eJpm -----END PGP SIGNATURE----- --OXfL5xGRrasGEqWY--
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