From owner-freebsd-hackers Mon Dec 7 13:09:06 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA16237 for freebsd-hackers-outgoing; Mon, 7 Dec 1998 13:09:06 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from caladan.tdx.co.uk (caladan.tdx.co.uk [195.188.177.4]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id NAA16232 for ; Mon, 7 Dec 1998 13:09:04 -0800 (PST) (envelope-from kpielorz@tdx.co.uk) Received: from tdx.co.uk (lorca-tx.tdx.co.uk [195.188.177.242]) by caladan.tdx.co.uk (8.9.1a/8.9.1) with ESMTP id VAA60074; Mon, 7 Dec 1998 21:08:46 GMT Message-ID: <366C43DD.A7DA16F4@tdx.co.uk> Date: Mon, 07 Dec 1998 21:08:45 +0000 From: Karl Pielorz Organization: TDX - The Digital eXchange X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en MIME-Version: 1.0 To: "Kenneth D. Merry" CC: "Ron G. Minnich" , hackers@FreeBSD.ORG Subject: Re: write combining memory on pci References: <199812072105.OAA07499@panzer.plutotech.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG "Kenneth D. Merry" wrote: > > Ron G. Minnich wrote... > > any good ideas on how to turn this on in 3.0 for a given memory address > > range? > > Isn't there usually a BIOS option to do that? I think it's called USWC or > something like that. (Uniform Speculative Write Combining?) I don't think > it generally covers a specific address range, though. Both my P-Pro systems have this option, and AFAIK it worked as above (i.e. 'all on' or 'all off')... Win NT survives with it on, until I try to use the sound card, and FreeBSD, Linux & Win'95 all die within seconds with it on... Which is a bit of a pitty, as I also seem to remember reading it gives a huge performance win on writes ;-) - Maybe there is such a thing as 'too fast'... -Kp To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message