From owner-freebsd-multimedia Thu Sep 16 20:57:48 1999 Delivered-To: freebsd-multimedia@freebsd.org Received: from mail.rdc1.nj.home.com (ha1.rdc1.nj.home.com [24.3.128.66]) by hub.freebsd.org (Postfix) with ESMTP id 54D4215420 for ; Thu, 16 Sep 1999 20:57:46 -0700 (PDT) (envelope-from garycor@home.com) Received: from home.com ([24.3.185.85]) by mail.rdc1.nj.home.com (InterMail v4.01.01.00 201-229-111) with ESMTP id <19990917035743.NIBR9848.mail.rdc1.nj.home.com@home.com>; Thu, 16 Sep 1999 20:57:43 -0700 Message-ID: <37E1BDA1.2B806174@home.com> Date: Fri, 17 Sep 1999 00:03:45 -0400 From: "Gary T. Corcoran" X-Mailer: Mozilla 4.6 [en] (Win95; U) X-Accept-Language: en MIME-Version: 1.0 To: Randall Hopper Cc: multimedia@FreeBSD.ORG Subject: Re: Is video overclocking risky? References: <19990916210053.A10590@ipass.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-multimedia@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Randall Hopper wrote: > > I have a new Matrox G200 PCI I picked up, and I notice I pick up about > a 10% XStone increase by using "overclock_mem" in XFree86 3.9.16. > > So in practice, is this risky? Or do you just risk video corruption? > > > From what little I know, I think this means it clocks the RAMDAC > faster, so it (along with the memory) is being pushed. At high resolutions > and refresh rates when the RAMDAC is already up toward the high end of its > limits, I think this means it'll be running closer to or past the spec freq > limit (maybe pulling more current than it was designed to). Is this > right in practice? Whenever you clock chips beyond their specified limit, you risk overheating them. While this may cause nothing but extra heat in the short term, in the long term it can cause premature failure of your chips (video board) [e.g. due to accelerated electro-migration of the "wires" in your chips]. I'm not familiar with exactly what "overclock_mem" means, but I suppose it also may depend on your board manufacturer. For example, (at least in the past) Diamond was famous for pushing their "normal" clock rates up to the edge so they'd get better performance in the benchmarks. I don't think I'd want to overclock my old Diamond video board because of that... Gary To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message