From owner-freebsd-performance@FreeBSD.ORG Wed Mar 12 03:42:57 2008 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D555F106566B; Wed, 12 Mar 2008 03:42:57 +0000 (UTC) (envelope-from markir@paradise.net.nz) Received: from smtp5.clear.net.nz (smtp5.clear.net.nz [203.97.33.68]) by mx1.freebsd.org (Postfix) with ESMTP id 9F3128FC17; Wed, 12 Mar 2008 03:42:57 +0000 (UTC) (envelope-from markir@paradise.net.nz) Received: from zmori.markir.net (121-73-161-240.dsl.telstraclear.net [121.73.161.240]) by smtp5.clear.net.nz (CLEAR Net Mail) with ESMTP id <0JXL006KZMBHC010@smtp5.clear.net.nz>; Wed, 12 Mar 2008 16:42:56 +1300 (NZDT) Date: Wed, 12 Mar 2008 16:42:39 +1300 From: Mark Kirkwood In-reply-to: <47D71F6F.2090600@paradise.net.nz> To: Ivan Voras Message-id: <47D7512F.5020006@paradise.net.nz> MIME-version: 1.0 Content-type: text/plain; charset=UTF-8; format=flowed Content-transfer-encoding: 7bit References: <571396.91912.qm@web50512.mail.re2.yahoo.com> <47D71F6F.2090600@paradise.net.nz> User-Agent: Thunderbird 2.0.0.9 (X11/20071203) Cc: freebsd-performance@freebsd.org Subject: Re: pgbench results X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Mar 2008 03:42:58 -0000 Mark Kirkwood wrote: > Ivan Voras wrote: >> >> The thing is - I *do* have a similar setup here: HP DL370 G5, 2x4-core >> 1.86 GHz, 4 GB RAM, 6 drives in RAID10, 512 MB cache (can pull > 200 >> MB/s off the array), with all settings like in the posted link except >> shared_buffer=1900 MB, and I "only" get this: >> >> tps = 2834.026175 (including connections establishing) >> tps = 2839.080739 (excluding connections establishing) >> >> This is still far bellow ~~ 4500 trans/s from the link and I wonder if >> my results are within what I should be getting. The benchmark in the >> link above was done with faster CPUs (but I'm not CPU bound - at least >> 30% idle), but with 3 times the memory and I'm guessing more memory >> would help here, but I'm not sure. >> >> What's strange is that toggling synchronous_commit doesn't have a >> significant effect on performance (it does increase CPU idle time). With >> synchronous_commit=off, I get: >> >> tps = 2886.980477 (including connections establishing) >> tps = 2891.776081 (excluding connections establishing) >> >> > > The article refers to a controller with a battery backed write cache - > that could easily explain the difference if you do not have one (he's > paying nothing for fsync wheres you are). > Hmm - somehow read right past the bit where you say you have a 512MB cache - sorry! However, worth checking it is set to write-back rather than write-through. Cheers Mark