X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 09F699FB249 for ; Thu, 14 Sep 2006 18:36:30 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 26259-10 for ; Thu, 14 Sep 2006 21:36:25 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey- Received: from pro25.abac.com (pro25.abac.com [66.226.64.26]) by postgresql.org (Postfix) with ESMTP id 574019FB232 for ; Thu, 14 Sep 2006 18:36:24 -0300 (ADT) Received: from [192.168.0.3] (wsip-70-167-125-69.sd.sd.cox.net [70.167.125.69]) (authenticated bits=0) by pro25.abac.com (8.13.8/8.13.8) with ESMTP id k8ELaEUb010013 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 14 Sep 2006 14:36:16 -0700 (PDT) (envelope-from cjames@modgraph-usa.com) Message-ID: <4509CB04.4020605@modgraph-usa.com> Date: Thu, 14 Sep 2006 14:35:00 -0700 From: "Craig A. James" User-Agent: Thunderbird 1.5.0.5 (X11/20060719) MIME-Version: 1.0 To: Alan Hodgson CC: pgsql-performance@postgresql.org Subject: Re: RAID 0 not as fast as expected References: <450999EC.8070601@modgraph-usa.com> <200609141136.03345@hal.medialogik.com> In-Reply-To: <200609141136.03345@hal.medialogik.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests= X-Spam-Level: X-Archive-Number: 200609/175 X-Sequence-Number: 20861 Alan Hodgson wrote: > On Thursday 14 September 2006 11:05, "Craig A. James" > wrote: >> I'm experiment with RAID, looking for an inexpensive way to boost >> performance. I bought 4 Seagate 7200.9 120 GB SATA drives and two SIIG >> dual-port SATA cards. (NB: I don't plan to run RAID 0 in production, >> probably RAID 10, so no need to comment on the failure rate of RAID 0.) >> > > Are those PCI cards? If yes, it's just a bus bandwidth limit. Ok, that makes sense. One SATA disk = 52 MB/sec 4-disk RAID0 = 106 MB/sec PCI at 33 MHz x 32 bits (4 bytes) = 132 MB/sec. I guess getting to 80% of the theoretical speed is as much as I should expect. Thanks, Craig