From owner-freebsd-smp Tue Feb 9 09:13:24 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA10615 for freebsd-smp-outgoing; Tue, 9 Feb 1999 09:13:24 -0800 (PST) (envelope-from owner-freebsd-smp@FreeBSD.ORG) Received: from fast.cs.utah.edu (fast.cs.utah.edu [155.99.212.1]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA10610 for ; Tue, 9 Feb 1999 09:13:23 -0800 (PST) (envelope-from vanmaren@fast.cs.utah.edu) Received: (from vanmaren@localhost) by fast.cs.utah.edu (8.9.1/8.9.1) id KAA17064; Tue, 9 Feb 1999 10:13:10 -0700 (MST) Date: Tue, 9 Feb 1999 10:13:10 -0700 (MST) From: Kevin Van Maren Message-Id: <199902091713.KAA17064@fast.cs.utah.edu> To: Thierry.Herbelot@alcatel.fr, smp@FreeBSD.ORG Subject: Re: Mixing P2 Types Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Well, it *should* work, but they will both have to run at the speed of the slowest processor. The only problem with that is Intel has added multiplier-locking to many of the Pentium II processors, preventing them from running if the multiplier is wrong. If they just locked the multiplier, you would have processors at different speeks (probably okay), but they won't POST if the multiplier is changed. Allegedly the multiplier isn't locked for `older' P-IIs with the locking if they are running at 66MHz bus. There are a few high-end machines that supported unequal Pentium processors ($80k+ range), and some of the Quad Pro boards could set the multiplier for the pairs of CPUs independantly, but I don't know of any Pentium II board that will do that. As for the SMP spec, that is true. However, Intel has said that they will not support mixing speeds/caches on the Xeon line, although (I believe) Compaq has said that they will. It it wasn't for the multiplier locking on the newer P-IIs, I'd tell you to get a 350 (or faster) CPU and the P2B-DS, and run the 350 at 266 until you upgraded to a second 350. The faster bus makes a bigger difference under SMP due to increased usage of the shared bus, and the 350 isn't much more than the 333. Maybe getting two 350s isn't too far out of reach? Kevin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message