From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 7 Aug 2001 11:17:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 7 Aug 2001 11:17:00 -0400 Received: from sdsl-208-184-147-195.dsl.sjc.megapath.net ([208.184.147.195]:28736 "EHLO bitmover.com") by vger.kernel.org with ESMTP id ; Tue, 7 Aug 2001 11:16:43 -0400 Date: Tue, 7 Aug 2001 08:16:52 -0700 From: Larry McVoy To: Rob Landley Cc: Paul Flinders , lm@bitmover.com, linux-kernel@vger.kernel.org Subject: Re: SIS 630E perf problems? Message-ID: <20010807081652.A11619@work.bitmover.com> Mail-Followup-To: Rob Landley , Paul Flinders , lm@bitmover.com, linux-kernel@vger.kernel.org In-Reply-To: <200108061713.f76HDaj16575@work.bitmover.com> <3B6F14E2.3030209@ftel.co.uk> <01080618523906.04153@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0.1i In-Reply-To: <01080618523906.04153@localhost.localdomain>; from landley@webofficenow.com on Mon, Aug 06, 2001 at 06:52:39PM -0400 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > I've used a few funky SIS chipsets, on and off, for a long time now, and they > always have one leeeetle problem... > > Try benchmarking it with a lower screen resolution (like 640x480x256 colors). > If the video is sharing main memory, it's sharing the memory bandwidth as > well. So you've basically got a constant ultra-high-priority DMA going to > the screen, sucking up bandwidth and fighting with everything else. > (Everything else MUST lose or the display would sparkle. > 1280x1024x32bitsx70hz is HOW much bandwidth we're talking here?) OK, a copuple of updates on this: I wasn't running X when I ran the benchmarks. I played around with the bios settings enough to make the machine not pass POST anymore so I reset the CMOS. Doing that, plus telling the system to autodetect DRAM clocks dropped the latencies down to 260ns outside of X and 281ns with X running. Still not fantastic but good enough I suppose. In reference to the fans that someone else mentioned: I think it is the CPU fan making the noise. Regardless, the MTBF of the power supply fans is one year. I have about a dozen of generation 1 of these bookpcs and the fans all started failing at 1 year and frying the power supplies. Those dinky power supplies are hard to find so you want to avoid this. We bought a pile of fans and replaced them all; one benefit is that the higher quality fans are much less noisy. Something to look into. -- --- Larry McVoy lm at bitmover.com http://www.bitmover.com/lm