From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Bevand Subject: Re: 1x 3ware controllers vs. 2x 3ware controllers Date: Fri, 30 Jul 2004 17:00:51 +0200 Sender: linux-raid-owner@vger.kernel.org Message-ID: References: <200407300815.18296.mrwatts@fast24.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200407300815.18296.mrwatts@fast24.co.uk> To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Mark Watts wrote: > With the performance issues I'm seeing with the 8506-4LP's I have, I wouldn't > recommend them to anyone currently... > > The thread on LKML from a few days ago about mke2fs -j and 8506-4LP says it > all, but basically and reasonable amount of I/O brings a Dual Opteron system > to its knees. > And by reasonable I mean copying ISO images from a usb2 drive to a raid 5 (4 x > 250GB maxtor) or even just formatting a 600MB partition. I would be interested to see the output of 'vmstat 1' while your system is so slow. IMHO you shouldn't draw such conclusion ("reasonable amount of I/O brings a Dual Opteron system to its knees") from your particular case. The 3 HT links of the Opteron make this CPU particularly adapted to I/O operations. Personnaly, on a dual Opteron, I am able to read datas from 4 SATA disks at about 225 MB/s, with CPU time used at about 32%, awd with a system still reasonably responsive. -- Marc Bevand http://www.epita.fr/~bevand_m Computer Science School EPITA - System, Network and Security Dept.