From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2013 invoked by alias); 27 Mar 2013 15:11:20 -0000 Mailing-List: contact cygwin-xfree-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-xfree-owner@cygwin.com Reply-To: cygwin-xfree@cygwin.com Mail-Followup-To: cygwin-xfree@cygwin.com Received: (qmail 1981 invoked by uid 89); 27 Mar 2013 15:11:11 -0000 X-Spam-SWARE-Status: No, score=-2.7 required=5.0 tests=AWL,BAYES_00,KHOP_THREADED,RCVD_IN_DNSWL_NONE,RCVD_IN_HOSTKARMA_YE autolearn=ham version=3.3.1 Received: from nm1-vm8.bt.bullet.mail.ir2.yahoo.com (HELO nm1-vm8.bt.bullet.mail.ir2.yahoo.com) (212.82.99.232) by sourceware.org (qpsmtpd/0.84/v0.84-167-ge50287c) with ESMTP; Wed, 27 Mar 2013 15:11:08 +0000 Received: from [212.82.98.47] by nm1.bt.bullet.mail.ir2.yahoo.com with NNFMP; 27 Mar 2013 15:11:05 -0000 Received: from [77.238.189.17] by tm8.bt.bullet.mail.ir2.yahoo.com with NNFMP; 27 Mar 2013 15:11:05 -0000 Received: from [127.0.0.1] by smtp817.mail.ird.yahoo.com with NNFMP; 27 Mar 2013 15:11:05 -0000 X-Yahoo-SMTP: u.JgLvyswBBMp9ZJJfsX14qmYb3T2ivhMAr6OupnxLpNQEFZ9g-- X-Rocket-Received: from [192.168.1.73] (jon.turney@109.155.6.100 with plain) by smtp817.mail.ird.yahoo.com with SMTP; 27 Mar 2013 15:11:05 +0000 GMT Message-ID: <51530C21.8000203@dronecode.org.uk> Date: Wed, 27 Mar 2013 15:11:00 -0000 From: Jon TURNEY Reply-To: cygwin-xfree User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130307 Thunderbird/17.0.4 MIME-Version: 1.0 To: cygwin-xfree@cygwin.com CC: aaronkelley@hotmail.com Subject: Re: Cygwin/X causes NVIDIA GPU to turn on in Optimus systems References: In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-SW-Source: 2013-03/txt/msg00022.txt.bz2 On 26/03/2013 15:58, Aaron A. Kelley wrote: > I usually leave Cygwin/X open on my machine because I use it to access GUI > apps running in SSH terminals from time to time. Today I noticed that in an > Optimus environment, it is causing the NVIDIA GPU to kick in, which causes > the NVIDIA GPU to stay powered on when maybe it doesn’t need to. > > http://stuff.aaron-kelley.net/2013/03/cygxoptimus.png > > I went to the NVIDIA control panel and set xwin.exe specifically to use the > integrated GPU but it still says that xwin.exe is running on the NVIDIA GPU > when I run it. Cygwin/X must be doing something unusual at initialization > that makes the NVIDIA card feel like it has to kick on. I don’t have to > actually launch any X windows to see this occur, it happens moments after I > launch the Cygwin/X server. The Cygwin X server doesn't do anything special (and specifically, doesn't do any of the things listed in [1] to explicitly use the high-performance GPU), so if it's being allowed to use OpenGL on the high-performance GPU despite the application profile you have created, I would say that might be a bug in the optimus driver. Note that this policy does belong in your hands, not in XWin, as it cannot know if you are going to be running any X programs using OpenGL, and if you are, if you want high-performance rendering in them at the cost of additional power usage. As a workaround, you could start the X server with the -nowgl option added, which should prevent any use of native OpenGL, forcing the use of software rendering using mesa and see if that helps. > I haven’t been able to find anyone else mentioning this. It may be because > Optimus configurations aren’t very common. This also means that this issue > may be tricky to track down. I’m not sure if it will be easy to find > someone who knows about Cygwin/X development who also has access to an > Optimus environment. This might be something that has to go for NVIDIA for > them to fix in their drivers, but it’d be nice to know a little more about > the issue before trying to get in touch with them. > > I’m interested in doing anything I can do help address this but I don’t know > where to begin, so I’m welcoming your feedback. For a start, you could look for the GL_VENDOR and GL_RENDERER lines in /var/log/xwin/XWin.0.log to confirm that XWin also thinks it is using the high-performance GPU. [1] http://developer.download.nvidia.com/devzone/devcenter/gamegraphics/files/OptimusRenderingPolicies.pdf -- Jon TURNEY Volunteer Cygwin/X X Server maintainer -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://x.cygwin.com/docs/ FAQ: http://x.cygwin.com/docs/faq/