From owner-freebsd-hardware Thu Jul 1 21:23:27 1999 Delivered-To: freebsd-hardware@freebsd.org Received: from mercury.gfit.net (ns.gfit.net [209.41.124.90]) by hub.freebsd.org (Postfix) with ESMTP id 1A91814CD5 for ; Thu, 1 Jul 1999 21:23:23 -0700 (PDT) (envelope-from tom@embt.com) Received: from paranor.embt.net (timembt.iinc.com [206.67.169.229]) by mercury.gfit.net (8.8.8/8.8.8) with SMTP id XAA12867; Thu, 1 Jul 1999 23:23:44 -0500 (CDT) (envelope-from tom@embt.com) Message-Id: <3.0.3.32.19990702002317.007170bc@mail.embt.com> X-Sender: tembt@mail.embt.com X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3 (32) Date: Fri, 02 Jul 1999 00:23:17 -0400 To: junkmale@xtra.co.nz From: Tom Embt Subject: Re: dual CPU compatibility issues Cc: freebsd-hardware@freebsd.org In-Reply-To: <377c2652.750a.0@actrix.gen.nz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org At 02:39 PM 7/2/99 nzst, you wrote: >I have an old DEC box which supports a dual processor setup. I've obtained a >Pentium 120 chip (the maximum speed supported by this box). I'm in the process >of tracking down another P120. > >How compatible does the second CPU have to be with the first? Is it enough >to be another Pentium 120? Do they have to be from the same batch or something? >- >Dan Langille > Not just any CPU will work! The CPU's should be the same stepping number, and preferably be type "SSS" CPUs (the last S is crucial). In the early-mid Pentium days, Intel had some difficulty manufacturing perfect chips, and thus sold some of the imperfect chips with certain restrictions on core voltage, timings, and (you got it!) SMP capability. Following a very productive (read: lucky) search on infoseek, it looks like you'll be wanting a SY033, SK110, or Q0776. If your board requires 82498/82493 or 82497/82492 compliant cache timings then the SK110 and Q0776 may not work. The good news is that all SMP-capable 120's are of the same stepping number, and should interoperate (aside from the above mentioned cache limitation). See the following links for more info: http://www.asus.com.tw/Products/TECHREF/CPU/Intel/intel-120.html http://www.asus.com.tw/Products/TECHREF/CPU/Intel/intel-ref.html http://www.asus.com.tw/Products/TECHREF/CPU/Intel/intel.html I do, however, see no reason why you couldn't mix and match P120's and P133's OR use a pair of P150's and jumper them at a 60MHz bus and 2x multiplier. Hope this helped, ------------------------------------------------------------------ "You're one of those condescending Unix computer users!" "Here's a nickel, kid. Get yourself a better computer" - Dilbert. Tom Embt ICQ UIN: 11245398 tom@embt.com d:-)> To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message