Received: from makus.postgresql.org ([98.129.198.125]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TLgrP-0005OC-3U for pgsql-performance@postgresql.org; Tue, 09 Oct 2012 20:57:03 +0000 Received: from smtp.01.com ([199.36.142.181]) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TLgrN-0000O0-NV for pgsql-performance@postgresql.org; Tue, 09 Oct 2012 20:57:02 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp-out-1.01.com (Postfix) with ESMTP id 51FE82CD014 for ; Tue, 9 Oct 2012 15:57:01 -0500 (CDT) X-Virus-Scanned: amavisd-new at smtp-out-1.01.com Received: from smtp.01.com ([127.0.0.1]) by localhost (smtp-out-1.01.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6elQhvtH8L8c for ; Tue, 9 Oct 2012 15:57:01 -0500 (CDT) Received: from smtp.01.com (localhost.localdomain [127.0.0.1]) by smtp-out-1.01.com (Postfix) with ESMTP id 2AAC52CD010 for ; Tue, 9 Oct 2012 15:57:01 -0500 (CDT) Received: from Sidney-Stratton.local (70-36-143-92.dsl.dynamic.sonic.net [70.36.143.92]) by smtp-out-1.01.com (Postfix) with ESMTPSA id CB6E82CD00A for ; Tue, 9 Oct 2012 15:57:00 -0500 (CDT) Message-ID: <50748F9B.10008@agliodbs.com> Date: Tue, 09 Oct 2012 13:56:59 -0700 From: Josh Berkus Organization: PostgreSQL Experts Inc. User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:15.0) Gecko/20120907 Thunderbird/15.0.1 MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: Hyperthreading (was: Two identical systems, radically different performance) References: In-Reply-To: X-Enigmail-Version: 1.4.4 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -1.9 (-) X-Archive-Number: 201210/91 X-Sequence-Number: 48050 On 10/9/12 1:12 PM, Craig James wrote: > I've confirmed that hyperthreading causes a huge drop in performance on a > 2x4-core Intel Xeon E5620 2.40GHz system. The bottom line is: > > ~3200 TPS max with hyperthreading > ~9000 TPS max without hyprethreading Oh, interesting! This is the first time I've seen results like this on a later Linux kernel and processor. I thought Intel had licked the "hyperthreading penalty". -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com