I'm running locally now and am seeing the same behavior. Running with --SingleThreaded makes no difference.
Cory On Mon, Feb 2, 2009 at 9:53 AM, Adrian Egli OpenSceneGraph (3D) < [email protected]> wrote: > Hi J-S > > i am working with NVidia GPU, and i have same behaviour. So there should be > another problem than the busy wait. Of course can VSync give some problem in > performance or at least we get a smaller FPS displayed. But here we have > some strang behavior of our osgViewer (renderer). My there is a bug inside > the synchronisation. > > But what i guess is: > When we are running under --SingleThreaded : > > bool GraphicsWindowWin32::realizeImplementation() > wglMakeCurrent > SwapBuffers > > all are called in the same thread. > > if we are working without singlethreaded option, then the realize get call > in the "master" thread and in the others wgl based method call get called in > a second thread. may the operating system (driver) understand, that there > must be more than one thread in the "world" and starts an extra > synchronisation which cause the CPU overload. > > /adrian > > > 2009/2/2 Jean-Sébastien Guay <[email protected]> > > Hi Cory, >> >> I'll have to defer to others on the situation under Windows when doing >>> remote desktop. My guess is that it's likely to be a driver issue. >>> >> >> Well, using Remote Desktop adds a variable into the mix for sure, so >> eliminating this and running the app locally would eliminate one possible >> thing. >> >> About one core being pegged, some video drivers implement vsync as a busy >> wait, which means that the CPU is not really pegged, it just looks like >> that. If you were to actually run real code on that core, along with OSG, >> you would see that that code would run at a normal speed because the vsync >> busy wait would relinquish the CPU while it's waiting for the next frame to >> start. >> >> So my guess is that your ATI drivers are doing this, and what you're >> seeing is just the idle time between frames being counted as active time by >> Process Explorer because it's implemented as a busy wait. Of course, I'm >> speculating here, you'll have to run a real app (not just osgviewer) to see >> for yourself. >> >> Note also that ATI's OpenGL drivers have never been the best... Though >> they say they're getting better, they have a long way to go. So there might >> be some of that here. >> >> Hope this helps, >> >> J-S >> -- >> ______________________________________________________ >> Jean-Sebastien Guay [email protected] >> http://www.cm-labs.com/ >> http://whitestar02.webhop.org/ >> >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > > > > -- > ******************************************** > Adrian Egli > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > >
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