From owner-freebsd-questions Thu Aug 2 8:33:29 2001 Delivered-To: freebsd-questions@freebsd.org Received: from mail4.mx.voyager.net (mail4.mx.voyager.net [216.93.66.203]) by hub.freebsd.org (Postfix) with ESMTP id 454A837B401 for ; Thu, 2 Aug 2001 08:33:25 -0700 (PDT) (envelope-from mhagerty@voyager.net) Received: from thunderbird.voyager.net (216-93-124-123.mdmmi.voyager.net [216.93.124.123]) by mail4.mx.voyager.net (8.10.2/8.10.2) with ESMTP id f72FXJZ11772; Thu, 2 Aug 2001 11:33:22 -0400 (EDT) Message-Id: <5.0.2.1.2.20010802111855.0184f060@pop.voyager.net> X-Sender: mhagerty@pop.voyager.net X-Mailer: QUALCOMM Windows Eudora Version 5.0.2 Date: Thu, 02 Aug 2001 11:34:56 -0400 To: Hassan Halta , From: Matthew Hagerty Subject: Re: 2 CPUs under FreeBSD In-Reply-To: <20010802005047.T29027-100000@quark.cs.earlham.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG At 12:53 AM 8/2/2001 -0500, Hassan Halta wrote: >Hi, > >We are running FreeBSD 4.3 Release, and we have 2 CPUs in our server. We >configured the Kernel to realize the existence of the 2nd CPU, and >everything seems to be working fine. However we have the problem with TOP. >It always shows either CPU to be using 0.00%, even when the hard drive is >hammered with some heavy processes, it's always 0.00%. > >I was wondering what you guys can advise in this matter, or what are the >steps to do the whole thing right. > >Thanks, >Hassan Having two CPUs in hardware and supported by the OS does not mean applications will necessarily take advantage of them. An application has to be written in such a way that the OS can execute it on multiple processors if available. I would say that TOP is *not* such and application, and you did not mention what you were running on this machine. Also, heavy disk I/O is not an indicator of heavy load on your server, it is an indication that you need more memory and a better disk subsystem, i.e. SCSI-160, a RAID, or simply more servers to even the disk load. During heavy disk I/O the CPU will more likely be 99.9% idle since it is waiting for the slow disk to finish. Something CPU intensive would be calculating the next prime number or processing weather patterns, etc. Most Internet based serving, i.e. HTTP, SMTP, FTP, etc. is *not* processor intensive, so you should not see much CPU load. Internet services are more memory, bandwidth, and disk intensive, so that is where you should be upgrading your servers. Also, RDBMS systems *can* be processor intensive, but only if they are doing big complex queries. Otherwise, for database backends to web sites, etc. it is still mostly disk I/O because the queries being executed are simple lookups, updates, adds, and deletes. Faster drives and more memory will go a long way to making your server faster. Matthew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message