From owner-freebsd-questions@FreeBSD.ORG Thu Mar 13 05:58:20 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2F7CF106566C for ; Thu, 13 Mar 2008 05:58:20 +0000 (UTC) (envelope-from lreid@cs.okstate.edu) Received: from a.cs.okstate.edu (a.cs.okstate.edu [139.78.113.1]) by mx1.freebsd.org (Postfix) with ESMTP id 272898FC18 for ; Thu, 13 Mar 2008 05:58:20 +0000 (UTC) (envelope-from lreid@cs.okstate.edu) Received: from [127.0.0.1] (localhost [127.0.0.1]) by a.cs.okstate.edu (Postfix) with ESMTP id 4620B154D48 for ; Thu, 13 Mar 2008 00:58:19 -0500 (CDT) Message-ID: <47D8C274.5030107@cs.okstate.edu> Date: Thu, 13 Mar 2008 00:58:12 -0500 From: Reid Linnemann User-Agent: Thunderbird 2.0.0.6 (X11/20071211) MIME-Version: 1.0 To: freebsd-questions Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: DRI on radeon 9500 using too wide memory bus? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Mar 2008 05:58:20 -0000 I've had DRI running on a radeon 9500 for a while now, and at some point in time tracking 6-STABLE and continuing now on 7-STABLE I've started seeing rendering artifacts in gl in the form of a cross-hatch pattern of pixels that don't get filled. At first I figured the card was failing, but I remembered a fact about the 9500 that made me doublethink that. The radeon 9500 is an r300 chipset, and differs from the 9700 only in the width of the memory bus (128 bit vs 256 bit) and possibly clock speed. If memory serves, the chip itself had the capacity to address 256 bits, but most 9500s just went out the door with 128 bit memory. I remember at one point in time trying out a hack to the 9500 driver that enabled the 256 bit bus to see if I had a rebadged 9700, and had similar artifacts. So I decided to peruse my X logs, and sure enough I see: (--) RADEON(0): Mapped VideoRAM: 131072 kByte (256 bit DDR SDRAM) Is it possible that the radeon driver is using the 256 bus? Is there a way to force it to use a 128 bit bus? Has anyone else seen this? Thanks, Reid