X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 5135A9DC85F for ; Fri, 10 Mar 2006 10:16:06 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 72465-09 for ; Fri, 10 Mar 2006 10:16:09 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from pih-relay05.plus.net (pih-relay05.plus.net [212.159.14.132]) by postgresql.org (Postfix) with ESMTP id 058359DC80E for ; Fri, 10 Mar 2006 10:16:01 -0400 (AST) Received: from [213.162.97.75] (helo=mail.metronet.co.uk) by pih-relay05.plus.net with esmtp (Exim) id 1FHiPP-0005BE-Tt; Fri, 10 Mar 2006 14:15:59 +0000 Received: from mainbox.archonet.com (unknown [84.51.143.99]) by smtp.metronet.co.uk (MetroNet Mail) with ESMTP id B1B2C414B74; Fri, 10 Mar 2006 13:40:22 +0000 (GMT) Received: from [192.168.1.17] (client17.office.archonet.com [192.168.1.17]) by mainbox.archonet.com (Postfix) with ESMTP id 86683FF08; Fri, 10 Mar 2006 13:40:22 +0000 (GMT) Message-ID: <441181C6.3040401@archonet.com> Date: Fri, 10 Mar 2006 13:40:22 +0000 From: Richard Huxton User-Agent: Thunderbird 1.5 (X11/20051201) MIME-Version: 1.0 To: "H.J. Sanders" Cc: pgsql-performance@postgresql.org Subject: Re: x206-x225 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=0.121 required=5 tests=[AWL=0.121] X-Spam-Score: 0.121 X-Spam-Level: X-Archive-Number: 200603/122 X-Sequence-Number: 17559 H.J. Sanders wrote: > X206 IBM X226 > ---------------------- ------------------- > processor Pentium 4 3.2 > Ghz Xeon 3.0 Ghz > main memory 1.25 > GB 4 GB > discs 2 x SCSI RAID1 10000RPM > 1 x ATA 7200 RPM Noting that the SCSI discs are on the *slower* machine. > Time at X206 Time at X226 > -------------------- ------------------ > insert record (1 to 10000) 6 sec. 41 sec. > select record (1 to 10000) 4 4 > delete record (1 to 10000) 6 41 > > > This is ofcourse a totally unexpected results (you should think off the > opposite). Your ATA disk is lying about disk caching being turned off. Assuming each insert is in a separate transaction, then it's not going to do 10,000 / 6 = 1667 transactions/sec - that's faster than it's rotational speed. > Funny is that the select time is the same for both machines. Because you're limited by the speed to read from RAM. By the way - these sort of tests are pretty much meaningless in any practical terms. -- Richard Huxton Archonet Ltd