X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id 6902F11F60A2 for ; Wed, 26 Apr 2006 12:18:19 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 33483-07 for ; Wed, 26 Apr 2006 12:18:00 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from exchange.g2switchworks.com (mail.g2switchworks.com [63.87.162.25]) by postgresql.org (Postfix) with ESMTP id 3F8D111F60B1 for ; Wed, 26 Apr 2006 12:17:59 -0300 (ADT) Received: from 10.10.1.37 ([10.10.1.37]) by exchange.g2switchworks.com ([10.10.1.2]) with Microsoft Exchange Server HTTP-DAV ; Wed, 26 Apr 2006 15:17:58 +0000 Received: from state.g2switchworks.com by mail.g2switchworks.com; 26 Apr 2006 10:17:58 -0500 Subject: Re: Large (8M) cache vs. dual-core CPUs From: Scott Marlowe To: "Jim C. Nasby" Cc: Bill Moran , pgsql-performance@postgresql.org In-Reply-To: <20060425235504.GO97354@pervasive.com> References: <20060425141435.6c8c163c.wmoran@collaborativefusion.com> <1145990018.23538.234.camel@state.g2switchworks.com> <20060425235504.GO97354@pervasive.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1146064678.23538.252.camel@state.g2switchworks.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Wed, 26 Apr 2006 10:17:58 -0500 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200604/606 X-Sequence-Number: 18690 On Tue, 2006-04-25 at 18:55, Jim C. Nasby wrote: > On Tue, Apr 25, 2006 at 01:33:38PM -0500, Scott Marlowe wrote: > > On Tue, 2006-04-25 at 13:14, Bill Moran wrote: > > > I've been given the task of making some hardware recommendations for > > > the next round of server purchases. The machines to be purchased > > > will be running FreeBSD & PostgreSQL. > > > > > > Where I'm stuck is in deciding whether we want to go with dual-core > > > pentiums with 2M cache, or with HT pentiums with 8M cache. > > > > Given a choice between those two processors, I'd choose the AMD 64 x 2 > > CPU. It's a significantly better processor than either of the Intel > > choices. And if you get the HT processor, you might as well turn of HT > > on a PostgreSQL machine. I've yet to see it make postgresql run faster, > > but I've certainly seen HT make it run slower. > > Actually, believe it or not, a coworker just saw HT double the > performance of pgbench on his desktop machine. Granted, not really a > representative test case, but it still blew my mind. This was with a > database that fit in his 1G of memory, and running windows XP. Both > cases were newly minted pgbench databases with a scale of 40. Testing > was 40 connections and 100 transactions. With HT he saw 47.6 TPS, > without it was 21.1. > > I actually had IT build put w2k3 server on a HT box specifically so I > could do more testing. Just to clarify, this is PostgreSQL on Windows, right? I wonder if the latest Linux kernel can do that well... I'm guessing that the kernel scheduler in Windows has had a lot of work to make it good at scheduling on a HT architecture than the linux kernel has.