Received: from makus.postgresql.org ([98.129.198.125]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TNmrF-0007XG-Mv for pgsql-performance@postgresql.org; Mon, 15 Oct 2012 15:45:33 +0000 Received: from host36.ns3.it ([80.79.54.36] helo=mail.opinioni.net) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TNmr9-0001tD-24 for pgsql-performance@postgresql.org; Mon, 15 Oct 2012 15:45:32 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.opinioni.net (Postfix) with ESMTP id 458A84E22DD; Mon, 15 Oct 2012 17:48:07 +0200 (CEST) Received: from mail.opinioni.net ([127.0.0.1]) by localhost (opinioni.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id QhYHLMbZYXwN; Mon, 15 Oct 2012 17:48:07 +0200 (CEST) Received: from [192.168.1.50] (78-134-6-72.v4.ngi.it [78.134.6.72]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.opinioni.net (Postfix) with ESMTPS id 058D64E22DC; Mon, 15 Oct 2012 17:48:06 +0200 (CEST) Message-ID: <507C2F94.6040000@opinioni.net> Date: Mon, 15 Oct 2012 17:45:24 +0200 From: Andrea Suisani User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121011 Thunderbird/16.0.1 MIME-Version: 1.0 To: Craig James CC: Claudio Freire , pgsql-performance@postgresql.org Subject: Re: Two identical systems, radically different performance References: <5076D433.7090605@opinioni.net> <5076DA4E.80504@opinioni.net> <507BC8DE.9050109@opinioni.net> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -1.9 (-) X-Archive-Number: 201210/189 X-Sequence-Number: 48148 [cut] >> TPS including connection establishing, pgbench run in a single >> thread mode, connection made through unix socket, OS cache dropped >> and Postgres restarted for every run. >> >> those are the results: >> >> HT HT SYSFS DIS HT BIOS DISABLE >> -c -t r1 r2 r3 r1 r2 r3 r1 r2 r3 >> 5 20K 1641 1831 1496 2020 1974 2033 2005 1988 1967 >> 10 10K 2161 2134 2136 2277 2252 2216 1854 1824 1810 >> 20 5k 2550 2508 2558 2417 2388 2357 1924 1928 1954 >> 30 3333 2216 2272 2250 2333 2493 2496 1993 2009 2008 >> 40 2.5K 2179 2221 2250 2568 2535 2500 2025 2048 2018 >> 50 2K 2217 2213 2213 2487 2449 2604 2112 2016 2023 >> >> Despite the fact the results don't match my expectation > > You have a RAID1 with 15K SAS disks. I have a RAID10 with 8 7200 SATA > disks plus another RAID1 for the XLOG file system. Ten 7K SATA disks > on two file systems should be quite a bit faster than two 15K SAS > disks, right? I think you're right. But I never have the chance to try such a configuration in first person. But, yes, spreading I/O on two different subsystems (xlog and pgdata) and having pgdata on a RAID10 should surely outperform my RAID1 with 15K SAS disks. >> (I suspect that there's something wrong with the PERC >> because, having the controller cache enabled make no >> difference in terms of TPS), it seems strange that disabling >> HT from the bios will give lesser TPS that HT disable through >> sysfs interface. > > Well, all I can say is that I like my 3WARE controllers, and it's the > secondary reason why I moved away from Dell (the primary reason is > price). Something I surely will take into account the next time I will buy a new server. Andrea