Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id B82EB2E341F for ; Wed, 19 Dec 2007 08:49:49 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 39927-10 for ; Wed, 19 Dec 2007 08:49:45 -0400 (AST) Received: from oxford.xeocode.com (unknown [62.232.55.118]) by postgresql.org (Postfix) with ESMTP id B48A22E3375 for ; Wed, 19 Dec 2007 08:49:45 -0400 (AST) Received: from localhost ([127.0.0.1] helo=oxford.xeocode.com) by oxford.xeocode.com with esmtp (Exim 4.67) (envelope-from ) id 1J4yMY-0001JW-Pp; Wed, 19 Dec 2007 12:49:27 +0000 To: "Stuart Bishop" Cc: Subject: Re: Dual core Opterons beating quad core Xeons? In-Reply-To: <476908BB.5090408@stuartbishop.net> (Stuart Bishop's message of "Wed\, 19 Dec 2007 19\:04\:11 +0700") User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1 (gnu/linux) X-Draft-From: ("nnimap+mail01.enterprisedb.com:INBOX.performance" 3690) References: <476908BB.5090408@stuartbishop.net> From: Gregory Stark Organization: EnterpriseDB Date: Wed, 19 Dec 2007 12:49:26 +0000 Message-ID: <87k5nan92h.fsf@oxford.xeocode.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200712/279 X-Sequence-Number: 28095 "Stuart Bishop" writes: > For pgbench (PG 8.2 running Ubuntu), the Opteron is getting about 6x TPS > over the Xeon (3000+ TPS on Opteron vs ~500 on Xeon). Things get a little > better for Xeon with PG 8.3 (570-540 TPS). There was a problem in the past which affected Xeons. But I thought it had been mostly addressed. Xeons are (or were? these things are always changing) more sensitive to interprocess contention due to their memory architecture though. What are you actually doing in these transactions? Are they read-only? If not is fsync=off (which you don't want if you care about your data but you do if you're trying to benchmark the cpu). Are the crappy disks *identical* crappy disks? If they have different controllers or different drives (or different versions of the OS) then you might be being deceived by write caching on one set and not the other. If they're not read-only transactions and fsync=on then the TPS of 3000+ is not credible and this is likely. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's RemoteDBA services!