Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 6A30B9F931E for ; Tue, 12 Dec 2006 08:42:20 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-new, port 10024) with ESMTP id 86624-01 for ; Tue, 12 Dec 2006 08:42:10 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from ebrsrv01.ebravo.it (host53-205-static.34-85-b.business.telecomitalia.it [85.34.205.53]) by postgresql.org (Postfix) with ESMTP id F12529F9EED for ; Tue, 12 Dec 2006 08:42:13 -0400 (AST) Received: from [192.168.11.103] ([192.168.11.103]) by ebrsrv01.ebravo.it (8.11.6/8.12.5) with ESMTP id kBCCgAD25235 for ; Tue, 12 Dec 2006 13:42:10 +0100 Message-ID: <457EA39E.1020207@streppone.it> Date: Tue, 12 Dec 2006 13:42:06 +0100 From: Cosimo Streppone User-Agent: Mozilla Thunderbird 1.5 (X11/20051201) MIME-Version: 1.0 To: Postgresql Performance list Subject: Re: New to PostgreSQL, performance considerations References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200612/286 X-Sequence-Number: 22342 Luke Lonergan wrote: > Can you try this with just "-O3" versus "-O2"? Thanks to Daniel for doing these tests. I happen to have done the same tests about 3/4 years ago, and concluded that gcc flags did *not* influence performance. Moved by curiosity, I revamped those tests now on a test machine (single P4 @ 3.2 Ghz, with 2Mb cache and 512 Mb Ram). Here are the results: http://www.streppone.it/cosimo/work/pg/gcc.png In short: tests executed with postgresql 8.2.0, gcc version 3.4.3 20041212 (Red Hat 3.4.3-9.EL4), tps figures computed as average of 9 pgbench runs (don't ask why 9... :-), with exactly the same commands given by Daniel: "-O0" ~ 957 tps "-O1 -mcpu=pentium4 -mtune=pentium4" ~ 1186 tps "-O2 -mcpu=pentium4 -mtune=pentium4" ~ 1229 tps "-O3 -mcpu=pentium4 -mtune=pentium4" ~ 1257 tps "-O6 -mcpu=pentium4 -mtune=pentium4" ~ 1254 tps I'm curious now to get the same tests run with a custom-cflags-compiled glibc. -- Cosimo