From owner-freebsd-performance@FreeBSD.ORG Tue Apr 25 13:07:40 2006 Return-Path: X-Original-To: freebsd-performance@freebsd.org Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2F12416A404 for ; Tue, 25 Apr 2006 13:07:40 +0000 (UTC) (envelope-from wmoran@collaborativefusion.com) Received: from mx00.pub.collaborativefusion.com (mx00.pub.collaborativefusion.com [206.210.89.199]) by mx1.FreeBSD.org (Postfix) with ESMTP id A820E43D5A for ; Tue, 25 Apr 2006 13:07:39 +0000 (GMT) (envelope-from wmoran@collaborativefusion.com) Received: from vanquish.pgh.priv.collaborativefusion.com (vanquish.pgh.priv.collaborativefusion.com [192.168.2.61]) by wingspan with esmtp; Tue, 25 Apr 2006 09:07:39 -0400 id 00056413.444E1F1B.000090FE Date: Tue, 25 Apr 2006 09:07:39 -0400 From: Bill Moran To: freebsd-performance@freebsd.org Message-Id: <20060425090739.8470143f.wmoran@collaborativefusion.com> Organization: Collaborative Fusion X-Mailer: Sylpheed version 2.2.0 (GTK+ 2.8.12; i386-portbld-freebsd6.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Dual-core CPU vs. very large cache 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: Tue, 25 Apr 2006 13:07:40 -0000 [First off, the list archives for this list don't seem to be searchable. I get the following error: Unable to read document excerpts '/usr/local/mailman/archives/private/freebsd-performance/htdig/db.excerpts' Did you run htdig?] So ... on to the question. We have some database servers that we're looking to replace with beefier hardware, mainly because we're expecting our customer base to grow a lot in the near future. The current hw is Dell 2850 servers. These are dual proc (each proc is hyperthreaded) with Dell PERC controllers driving 4 SCSI-320 disks in a RAID-10. We're doing our best to simulate high-load in the lab, and the database consistently bottlenecks on CPU usage. I'm assuming that the combination of plenty of RAM and high-speed disks has led to the CPU being the slowest part of the system. We're considering two alternatives for the newer hardware: 1) Intel HT CPUs with 8M cache 2) Intel dual-core procs Our current Dells have 2M cache, and I'm trying to determine whether the 8M cache will make a significant difference or not. Can someone recommend a testing procedure for determining whether adding cache is worthwhile or not? I can simulate a test load at any time, but I don't know how to tell whether the cache is the bottleneck of the CPU or not. -- Bill Moran Collaborative Fusion Inc.