From owner-freebsd-questions Tue May 22 21:44:57 2001 Delivered-To: freebsd-questions@freebsd.org Received: from guru.mired.org (okc-65-26-235-186.mmcable.com [65.26.235.186]) by hub.freebsd.org (Postfix) with SMTP id 5C84E37B422 for <questions@freebsd.org>; Tue, 22 May 2001 21:44:51 -0700 (PDT) (envelope-from mwm@mired.org) Received: (qmail 60114 invoked by uid 100); 23 May 2001 04:44:50 -0000 From: Mike Meyer <mwm@mired.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15115.16450.249394.115359@guru.mired.org> Date: Tue, 22 May 2001 23:44:50 -0500 To: Kent Stewart <kstewart@urx.com> Cc: questions@freebsd.org Subject: Re: Dual Ppro motherboards In-Reply-To: <6338897@toto.iv> X-Mailer: VM 6.90 under 21.1 (patch 14) "Cuyahoga Valley" XEmacs Lucid X-face: "5Mnwy%?j>IIV\)A=):rjWL~NB2aH[}Yq8Z=u~vJ`"(,&SiLvbbz2W`;h9L,Yg`+vb1>RG% *h+%X^n0EZd>TM8_IB;a8F?(Fb"lw'IgCoyM.[Lg#r\ Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: <freebsd-questions.FreeBSD.ORG> List-Archive: <http://docs.freebsd.org/mail/> (Web Archive) List-Help: <mailto:majordomo?subject=help> (List Instructions) List-Subscribe: <mailto:majordomo?subject=subscribe%20freebsd-questions> List-Unsubscribe: <mailto:majordomo?subject=unsubscribe%20freebsd-questions> X-Loop: FreeBSD.ORG Kent Stewart <kstewart@urx.com> types: > I have always thought of MP systems as something that didn't run anything > faster but what they would do is run additional applications equally slowly. Yup, that's what they are. They're really nice if you have lots of applications that are otherwise i/o bound. For typical single-user use, they aren't so great. For Unix power users - who have a tendency to have other things going in the background - an extra processor is also a nice thing to have. Of course, if you're developing applications that run in one of those environments, having a second processor so you can do some testing in the environment is also nice. That's why I bought one. When it's not fast enough to be a workstation anymore, I'll probably go buy a single-CPU system, and keep this one around for a test system. It's going to be interesting to see what causes that to happen. > The compiler's on Cray's were the best the world had to offer in 1990. > However, when you turned on full MP and vector support, a 486-PC would out > compile it on a line for line basis. The PC was fast because it didn't have > to worry about pipelines and producing do-loops that could be run on more > than one processor. Another thing to consider is the architecture of the two machines. Crays was designed for crunching numbers, generally in large arrays. Doing character manipulation was a lot of work - you had to shift the word to the character you wanted then mask it off, so that while you were doing a lot more instructions per second than a conventional machine, you were also doing a lot more instructions for each unit of work. The end result was that unix character-crunching benchmarks on a Cray performed about as well as a fast minicomputer of the time. <mike -- Mike Meyer <mwm@mired.org> http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message