Date: Wed, 19 May 1999 09:58:31 -0400 From: Richard Cownie <tich@ma.ikos.com> To: "Kenneth D. Merry" <ken@plutotech.com>, Andreas.Pleschutznig@Schwab.COM (Pleschutznig Andreas) Cc: freebsd-smp@FreeBSD.ORG Subject: Re: Which MB, SCSI Controller any suggestions? Message-ID: <99051910385100.08661@par28.ma.ikos.com> References: <199905182339.RAA37246@panzer.plutotech.com>
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On Tue, 18 May 1999, Kenneth D. Merry wrote: > Pleschutznig, Andreas wrote... > > Either I'm blind (maybe) or it isn't stated anywhere I've looked so far, or > > ... But I'm looking for the answer to a couple of questions. > > [ I'll answer the questions I have some clue about ] > > > -) How many processors is FreeBSD capable to use efficiently? > > Generally you can have up to 4, but a guy at some company that I can't > remember the name of patched FreeBSD to work with their 8-way systems. > That company subsequently went out of business, so don't worry about 8-way > systems for now. That would be me, at Axil Computer this time last year. The machine was the Axil NX801 - 8 PentiumPro's and up to 8GB of DRAM. The same boards went into systems sold by DG and HP (NetServer LXr Pro8 ?). The kernel patches for 8 cpu's were not very big - just a couple of boot-time race conditions which didn't show up until you hit 6 cpu's. The hard bit was that the chipset had 2 IOAPIC's and lots of interrupt sources: I had a kludge that worked for a minimal system, and a plan to fix it properly, but it never got done before Axil went belly-up. These days I'm at Ikos Systems developing EDA software which can burn a lot of CPU and memory - and FreeBSD running on the Intel SC450NX quad-Xeon turns out to be the best development platform. We've bought a couple of machines from SAG Electronics (www.sagelec.com) and are very happy with them. Here's the configuration of the most recent one: Intel SC450NX 4 x Xeon-500MHz, 512K cache (Free swap to 4 x Xeon-550MHz when they become available) 4GB DRAM (16 x 256MB EDO DIMMs) Adaptec 2940U2W PCI-SCSI (onboard Symbios 53C896 crashes FreeBSD install) 6 x 9GB 7200rpm LVD SCSI disk This came to about $20K, which I believe is much much cheaper than the equivalent configuration from Dell/Compaq etc. We're running the 4.0-19990421 snapshot with a patch to /usr/src/sys/i386/i386/machdep.c to limit Maxmem to 4GB-64MB, and some tuning of kernel options. If you don't need the full 4GB DRAM then you can probably run FreeBSD 3.1 or 3.2 without much tuning (?) This machine certainly uses 4 cpu's efficiently for multiple user processes; I haven't done anything which would really test the kernel scalability so others are better placed to comment on that aspect. Good luck Richard Cownie (tich@ma.ikos.com) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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