Received: from localhost (unknown [200.46.204.184]) by developer.postgresql.org (Postfix) with ESMTP id AA8BE2E004A for ; Wed, 2 Apr 2008 03:12:28 -0300 (ADT) Received: from developer.postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 94431-04 for ; Wed, 2 Apr 2008 03:12:20 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from ptb-relay02.plus.net (ptb-relay02.plus.net [212.159.14.213]) by developer.postgresql.org (Postfix) with ESMTP id 8101A2E002C for ; Wed, 2 Apr 2008 03:12:21 -0300 (ADT) Received: from [80.229.150.39] (helo=mansionfamily.plus.com) by ptb-relay02.plus.net with esmtp (Exim) id 1JgwCp-0004Jn-5s for pgsql-performance@postgresql.org; Wed, 02 Apr 2008 07:12:19 +0100 Received: from [192.168.0.89] ([192.168.0.89]:1573) by mansionfamily.plus.com with [XMail 1.22 ESMTP Server] id for from ; Wed, 2 Apr 2008 07:17:17 +0100 Message-ID: <47F324B4.6010404@mansionfamily.plus.com> Date: Wed, 02 Apr 2008 07:16:20 +0100 From: James Mansion Organization: MsgWare User-Agent: Thunderbird 2.0.0.0 (Windows/20070326) MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: SSDs Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Plusnet-Relay: 59614b77486a8e17c53e728d0c2d438d X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200804/17 X-Sequence-Number: 29510 Tried harder to find info on the write cycles: found som CFs that claim 2million cycles, and found the Mtron SSDs which claim to have very advanced wear levelling and a suitably long lifetime as a result even with an assumption that the underlying flash can do 100k writes only. The 'consumer' MTrons are not shabby on the face of it and not too expensive, and the pro models even faster. But ... the spec pdf shows really hight performance for average access, stream read *and* write, random read ... and absolutely pants performance for random write. Like 130/s, for .5k and 4k writes. Its so pants it looks like a misprint and it doesn't seem to square with the review on tomshardware: http://www.tomshardware.com/2007/11/21/mtron_ssd_32_gb/page7.html Even there, the database IO rate does seem lower than you might hope, and this *might* be because the random reads are very very fast and the random writes ... aren't. Which is a shame, because that's exactly the bit I'd hope was fast. So, more work to do somewhere.