From owner-freebsd-questions Thu Feb 4 09:02:39 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA16739 for freebsd-questions-outgoing; Thu, 4 Feb 1999 09:02:39 -0800 (PST) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from smtp1.mindspring.com (smtp1.mindspring.com [207.69.200.31]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA16676 for ; Thu, 4 Feb 1999 09:02:26 -0800 (PST) (envelope-from Lawrence.Hughes@mindspring.com) Received: from lhughes ([38.183.110.20]) by smtp1.mindspring.com (8.8.5/8.8.5) with SMTP id LAA17502 for ; Thu, 4 Feb 1999 11:33:15 -0500 (EST) Message-ID: <06b101be505d$d2f9cf00$3a01010a@lhughes.secureit.com> From: "Lawrence Hughes" To: Subject: Re: Pentium II install Date: Thu, 4 Feb 1999 11:45:51 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3155.0 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3155.0 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG hmmmm.... so many fascinating things to sort out.... where to begin... 1. The Pentium II does in fact have two internal processors, one for Integer operations, one for Floating Point. These two units used to be sold independently (e.g. 386/387) but converged about the time of the i486. 2. Both the Integer unit and FP unit are used by most software today, Windows or otherwise. Very old fossil software might emulate the FP stuff in software, assuming no FP processor was present, but most chips made in the last few years include FP hardware. 3. There may be some x86 variants with multiple internal integer functional units, to pass the one instruction/clock cycle limit, I'm not sure (haven't kept THAT close track of x86 lately). Even if they do, this is completely internal, and appears to be a single processor to the programmer (parallelism and scheduling is handled by something called a "stunt box" - and first showed up in Seymour Cray's CDC 6000 series computers.) Pretty much transparent to software (ok, you can play a few games to help out the stunt box for maximum parallelism - typically done by ordering machine instructions in the last phase of compiler optimization passes). 4. The PII can definitely be built in parallel configurations - with multiple chips - dual PII boards are readily available, and not even that outrageously expensive today. They can be wired for "twice the bang" or fault tolerant "let's both do the same thing, and recover if we don't agree" mode 5. With the traditional dual CPU (or quad, 6x, 8x, which takes somewhat more complex motherboards/backplanes), you can get fairly linear scaling of performance with added CPUs. Maybe 3.5X a 1 CPU system with 4 CPUs. 6. To harvest the performance possible on a SMP (Symmetric Multi Processor), your OS needs to support multi process correctly (can schedule any process on any available CPU) and/or multi-threading. Windows NT can do both. FreeBSD 3.0 supports allocating processes across multiple CPUs. (anyone happen to know if the FreeBSD pThreads supports SMP in 3.0, to spread threads in a single process across multiple CPUs?) 7. Win9x (slightly rewarmed barely 32-bit DOS and Win3.1) can't do much of anything with additional CPUs. Nor can anything from MS prior to those. Verstehe? -----Original Message----- From: gkaplan To: freebsd-questions@FreeBSD.ORG Date: Thursday, February 04, 1999 10:29 AM Subject: Pentium II install >I have been given to understand that the P II is inherently a dual >processor, and that under most if not all (ms) operating systems the >second processor will idle. The question is what if anything need to be >done during or after an initial FreeBSD installation needs to be done to >have a functioning dual processor system? > > >To Unsubscribe: send mail to majordomo@FreeBSD.org >with "unsubscribe freebsd-questions" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message