From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262348AbUBXRhB (ORCPT ); Tue, 24 Feb 2004 12:37:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262322AbUBXRgr (ORCPT ); Tue, 24 Feb 2004 12:36:47 -0500 Received: from delerium.kernelslacker.org ([81.187.208.145]:48832 "EHLO delerium.codemonkey.org.uk") by vger.kernel.org with ESMTP id S262336AbUBXRgE (ORCPT ); Tue, 24 Feb 2004 12:36:04 -0500 Date: Tue, 24 Feb 2004 17:34:44 +0000 From: Dave Jones To: Albert Cahalan Cc: linux-kernel mailing list , davem@redhat.com, Linus Torvalds Subject: Re: Intel vs AMD x86-64 Message-ID: <20040224173444.GL11203@redhat.com> Mail-Followup-To: Dave Jones , Albert Cahalan , linux-kernel mailing list , davem@redhat.com, Linus Torvalds References: <1077590524.8084.237.camel@cube> <20040224164404.GB10157@redhat.com> <1077635481.8120.300.camel@cube> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1077635481.8120.300.camel@cube> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 24, 2004 at 10:11:22AM -0500, Albert Cahalan wrote: > > so this isn't possible. The amd64 GART driver goes to great > > lengths to make sure it does update the northbridges on every > > CPU whenever something changes. > > Of course. That's the easy way; you won't need > to worry about memory interleave or out-of-bounds > prefetch if you keep everything coherent. > > I'm just saying it would be neat, and potentially > useful, to intentionally violate this. Of greatest > interest would be the 2-way Opteron boards that > only have RAM connected to the CPU closest to PCI. > The sidecar CPU :-) could be ignored. Why on earth would you want to do that ? It wouldn't buy you anything at all other than a world of pain. Dave