From owner-freebsd-hardware Fri Nov 8 05:38:43 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id FAA03418 for hardware-outgoing; Fri, 8 Nov 1996 05:38:43 -0800 (PST) Received: from groa.uct.ac.za (groa.uct.ac.za [137.158.128.7]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id FAA03393; Fri, 8 Nov 1996 05:38:30 -0800 (PST) Received: by groa.uct.ac.za via sendmail with stdio id for current@freebsd.org; Fri, 8 Nov 1996 15:34:29 +0200 (SAT) (Smail-3.2 1996-Jul-4 #2 built 1996-Oct-2) Message-Id: From: rv@groa.uct.ac.za (Russell Vincent) Subject: Large RAM on ASUS P/E-P55T2P4D To: jgreco@brasil.moneng.mei.com (Joe Greco) Date: Fri, 8 Nov 1996 15:34:28 +0200 (SAT) Cc: current@freebsd.org, hardware@freebsd.org In-Reply-To: <199610291827.MAA24642@brasil.moneng.mei.com> from "Joe Greco" at Oct 29, 96 12:27:22 pm X-Mailer: ELM [version 2.4 PL25] Content-Type: text Sender: owner-hardware@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Joe Greco wrote (about the ASUS P/E-P55T2P4D): > I can't get anything more than 192MB to work reliably on this board > (6 x 32MB SIMM modules) - unless we go with the mega mondo $$$$ 64MB > SIMM's.. and even those I have doubts about. We put the 4 that we > have on a P/I-P55T2P4 board and it refused to work until we relaxed > the RAM timing to 70ns. Gives me a sick feeling. Seems I may be encountering this problem on some of my 5 machines with 256MB, after all. Our supplier has just pointed me to pages 12-33 of: http://www.intel.com/design/pcisets/datashts/inte2.htm (which I am struggling to download on our poor international link). Apparently this document describes a method for increasing the current flow to DRAM (programatically) because as you put more chips into an Intel 430HX motherboard (probably any motherboard), the current flow drops, moving the trigger level (I had a nice little diagram drawn for me which would be tricky to duplicate here :-) ). This makes some sense to me (even with my poor technical knowledge) as the 4x64MB chips we are using are quite large. Reducing the DRAM timing to 70ns will also help, although, as you say, isn't suitable. If anyone does add some code for this, I would be most interested in testing it. I will try myself (when I can get the datasheet), but my programming skills are not good, so don't rely on me. :-) -Russell