From owner-freebsd-current Thu Jan 31 17:27:19 2002 Delivered-To: freebsd-current@freebsd.org Received: from canonware.com (dsl081-058-209.sfo1.dsl.speakeasy.net [64.81.58.209]) by hub.freebsd.org (Postfix) with ESMTP id 9C45037B400 for ; Thu, 31 Jan 2002 17:27:17 -0800 (PST) Received: by canonware.com (Postfix, from userid 1001) id 0C398F4; Thu, 31 Jan 2002 17:34:08 -0800 (PST) Date: Thu, 31 Jan 2002 17:34:08 -0800 From: Jason Evans To: =?iso-8859-1?Q?G=E9rard_Roudier?= Cc: Kenneth Culver , "Cameron, Frank" , Terry Lambert , David Malone , "'freebsd-current@freebsd.org'" Subject: Re: AMD AGP Bug Message-ID: <20020131173408.B63502@canonware.com> References: <20020131135127.V22577-100000@alpha.yumyumyum.org> <20020130225003.C2570-100000@gerard> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.2.5i In-Reply-To: <20020130225003.C2570-100000@gerard>; from groudier@free.fr on Wed, Jan 30, 2002 at 11:14:48PM +0100 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Wed, Jan 30, 2002 at 11:14:48PM +0100, Gérard Roudier wrote: > > Linux can be fixed, but the useless writes of the existing Athlons from > the very fast cache to the relatively very slow memory cannot. And all > Athlon users may well pay this penalty under any OS... unless we want to > disable caching. :) Have you done benchmarks to show that the speculative writes are useless often enough to cause enough memory bus contention that overall performance is degraded, despite the speedups when the speculative writes are valid? I suspect that AMD in fact performed such tests; otherwise they wouldn't have gone to the trouble of implementing speculative writes. Jason To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message