From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phillip Susi Subject: Re: Information resources Date: Fri, 25 Feb 2011 18:03:38 -0500 Message-ID: <4D68354A.2060803@cfl.rr.com> References: <4D66B699.7010803@cfl.rr.com> <4D67BEEA.3020207@cfl.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from cdptpa-omtalb.mail.rr.com (cdptpa-omtalb.mail.rr.com [75.180.132.121]) by gabe.freedesktop.org (Postfix) with ESMTP id 852F69E760 for ; Fri, 25 Feb 2011 15:03:39 -0800 (PST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Alex Deucher Cc: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org On 02/25/2011 03:38 PM, Alex Deucher wrote: > The CP firmware has nothing to do with the temperature. The CP > firmware is just a packet parser for reading in command buffers and > programming the register backbone. Just alike a CPU, the GPU runs at > whatever speed it's clock is set to. You can manually force lower > power states using sysfs. See the power management section of this > page: > http://wiki.x.org/wiki/RadeonFeature I have tried writing low to power_profile and it seems to make little to no difference. A cpu executing a tight loop busy waiting for something to do wastes a lot more power than one that has executed a HLT instruction, or used even better stop states to gate off clocks that are not needed. It seems to me that when there is nothing for the GPU to do, it also should stop executing instructions and gate off any unneeded clocks.