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Date: Thu, 17 Jan 2002 11:43:21 -0800 (PST)
From: "Randy.Dunlap" <rddunlap@osdl.org>
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To: Robert Love <rml@tech9.net>
cc: Barry Wu <wqb123@yahoo.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: how many cpus can linux support for SMP?
In-Reply-To: <1011253904.817.118.camel@phantasy>
Message-ID: <Pine.LNX.4.33L2.0201171141110.13155-100000@dragon.pdx.osdl.net>
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On 17 Jan 2002, Robert Love wrote:

| On Thu, 2002-01-17 at 01:59, Barry Wu wrote:
|
| > I am new to this mail list. I do not know how many CPUs linux can
| > support well using SMP. If some one knows, please give me
| > a reply. Thanks.
|
| 32.
|
| "well" though may mean many things and the answer depends on your
| workload.

On x86, using APICs, Pentium III maximum is 15 due to APIC addressing.
The IBM multiquad patch uses different APIC addressing (physical vs.
logical), so it goes beyond 15.
Pentium 4 APICs have addressing up to 255 IIRC, so they can do more
than P-III's 15.

-- 
~Randy

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