X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id C3D259FA2A1 for ; Tue, 12 Sep 2006 18:49:37 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 87617-02 for ; Tue, 12 Sep 2006 18:49:26 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from smtp.enternet.hu (smtp.enternet.hu [62.112.192.21]) by postgresql.org (Postfix) with ESMTP id 6282E9FA236 for ; Tue, 12 Sep 2006 18:49:26 -0300 (ADT) Received: from [83.216.41.252] (helo=[172.16.0.43]) by smtp.enternet.hu with esmtpa (Exim 4) id 1GNG88-000959-DA for pgsql-performance@postgresql.org; Tue, 12 Sep 2006 23:49:20 +0200 Message-ID: <45072B61.3080506@designaproduct.biz> Date: Tue, 12 Sep 2006 23:49:21 +0200 From: Laszlo Nagy User-Agent: Thunderbird 1.5.0.5 (Windows/20060719) MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: Poor performance on seq scan References: <450684EC.4090304@designaproduct.biz> <17034.1158079926@sss.pgh.pa.us> <45072130.6020508@modgraph-usa.com> In-Reply-To: <45072130.6020508@modgraph-usa.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=0.029 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200609/104 X-Sequence-Number: 20790 Craig A. James wrote: > > There IS a bug for SATA disk drives in some versions of the Linux > kernel. On a lark I ran some of the I/O tests in this thread, and > much to my surprise discovered my write speed was 6 MB/sec ... ouch! > On an identical machine, different kernel, the write speed was 54 MB/sec. My disks are running in SATA150 mode. Whatever it means. I'm using FreeBSD, and not just because it dynamically alters the priority of long running processes. :-) Laszlo