Date: Thu, 04 Feb 1999 23:19:49 -0800 From: Kent Stewart <kstewart@3-cities.com> To: Lawrence Hughes <Lawrence.Hughes@mindspring.com> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Pentium II install Message-ID: <36BA9B95.F101470A@3-cities.com> References: <06b101be505d$d2f9cf00$3a01010a@lhughes.secureit.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Lawrence Hughes wrote: > > hmmmm.... so many fascinating things to sort out.... where to begin... <snip> > > 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. It has also been known to go the other way. I saw a series of benchmarks about a year ago that had you losing 5% per cpu. The analysis was that state changes were eating the gains. There are some products that are designed to work in an SMP environment and they gain throughput with an increase in cpu's. > > 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?) I don't have the source but there is a system call PVM that runs on a series of computers as a virtual machine. It will run in a heterogenus environment but this can produce strange results if the numerics are vastly different between cpu's. A PC's 64 bit does not produce identical results to a DEC Alpha, which is one of the favorites because it produces identical answers to the older multi-headed Cray's. I am in the midst of compiling a program that works in that environment. The make, which uses f77, started 1:55 ago and we still have a ways to go. Kent > > 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 <gkaplan@castle.net> > To: freebsd-questions@FreeBSD.ORG <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 -- Kent Stewart Richland, WA mailto:kstewart@3-cities.com http://www.3-cities.com/~kstewart/index.html Hunting Archibald Stewart, b 1802 in Ballymena, Antrim Co., NIR http://www.3-cities.com/~kstewart/genealogy/archibald_stewart.html To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?36BA9B95.F101470A>