Hi Todd, It looks like the qwindowsglcontext.cpp file does not request a swap interval of 1 anywhere, which would mean you have to pick the option "always vsync, regardless of what application requests"-option if such a thing exists. If you did this and it makes no difference then the driver is broken :)
Another option is to disable the threaded renderer on windows using the environment variable QML_BAD_GUI_RENDER_LOOP, doing this would put it on par with X11/XCB. This is something we anyways need in order to support multiple toplevel QML windows as the current threaded implementation expects to block on a full buffer queue per window rather than swapBuffers to block immediately. The environment variable will switch to use the timer driven, GUI-only render loop. This also disables the vsync driven animations, but for a driver that ignores vsync, this is what we have to use. If we played nice, we would expose this behavior from the QPlatformIntegration / QPlatformGLContext so QtDeclarative could adapt properly, but we currently don't have API and implementation in place to catch this. cheers, Gunnar On Jan 16, 2012, at 1:45 AM, ext [email protected] wrote: > Well it looks like the slowness I'm seeing is due to the rendering thread > using all of the CPU. I tried toggling the nvidia driver settings for vsync > and triple-buffering but that doesn’t change the behavior. Is there anything > else I can try? Do other people see acceptable performance on Windows > currently? > > -Todd > >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On >> Behalf Of ext [email protected] >> Sent: Saturday, January 14, 2012 4:47 PM >> To: Storm-Olsen Marius (Nokia-MP/Austin); [email protected] >> Subject: Re: [Development] Status of QtDeclarative on Windows? >> >> It seems equally slow when running debug and release libs, but will double >> check later this weekend to make sure it's not user-error. I think it has >> more >> to do with running with a video card that doesn't provide much (if any?) >> hardware acceleration. But I was assuming that even in that case that QML2 >> would be just as good as QML1. Clearly something is causing that to not be >> the case. >> >> What's the expectation when using video cards that don't offer OpenGL >> hardware acceleration? >> >> -Todd >> >>> -----Original Message----- >>> From: Storm-Olsen Marius (Nokia-MP/Austin) >>> Sent: Saturday, January 14, 2012 9:12 AM >>> To: [email protected]; Rose Todd (Nokia-M/Alpharetta) >>> Subject: Re: [Development] Status of QtDeclarative on Windows? >>> >>> Are you sure you are at least running the release version of your >> application? >>> >>> Debug version uses the debug CRT libs (and a debug Qt which does the >>> same), so everything will be a lot slower than the end product. >>> >>> You cannot really evaluate performance with debug builds. >>> >>> -- >>> Sent from my Nokia N9 >>> On 1/13/12 23:12 ext [email protected] wrote: >>> Just for fun I’ve been playing with a medium-sized QML app that we had >>> written for 4.7/Symbian and porting it to Qt5/QML2. Mostly have been >>> working on Linux but the past few days I finally got around to >>> compiling Qt5 on Windows and playing around with the project enough so >>> that it would compile and run under qmlscene (it’s mostly qml/js with >>> a C++ plugin module as well). >>> >>> Anyway, the performance on my Windows box is horrible. ListView >>> scrolling, image loading, animations, everything is like it’s running >>> in quicksand. Is this expected? If not, what do I need to do to in >>> order to troubleshoot? This machine is relatively old and has a >>> crappy video card (older Nvidia Quadro), but it should be more than >>> good enough to run this app smoothly. Any tips or tricks to enable extra >> debug tracing? >>> >>> Thanks, >>> Todd >> _______________________________________________ >> Development mailing list >> [email protected] >> http://lists.qt-project.org/mailman/listinfo/development > _______________________________________________ > Development mailing list > [email protected] > http://lists.qt-project.org/mailman/listinfo/development _______________________________________________ Development mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/development
