I was thinking about this when a friend of mine asked me about the "Linux eye-candy". We were talking about the different implementations of "visual effects" on the desktop in the different operating systems. We both came to one realization: Of all implementations, the one which seems to tax the less system's resources is the MacOS X implementation. I'm not sure how Quartz gets all the goodies done, and the visual effects department in OS X don't seem to be radically different from the past three incarnations of the OS (Panther, Tiger, and now Leopard), except a few things here and there. Now, AFAIK, OS X visual effects are purely 2D based, which means that they do not actually tax the 3D pipelines of the GPUs, and hence, the GPUs have most of their resources available to do acceleration even with the "fancy" effects turned on on OS X.
Vista and Compiz utilize for their visual effects the 3D pipelines, as they (contrary to OS X) do actually perform window transformations and other 3D effects, without taxing much the system's CPU(s). This however has the downside effect of decreasing in most cases the performance of 3D applications when the "fancy visual effects" are turned on, a trade off many of us gladly take (is not like you cannot turn the effects off for running games or other 3D applications in either OS). While discussing this, my friend and I pondered what would be possible solutions to retain full rendering speed when running dedicated 3D apps (i.e, full screen) with the desktop effects turned on. As many users can tell, 3D performance does suffer quite a bit when you have running Compiz-Fusion/Beryl in the background and you launch a game. Even if the desktop is not being rendered, or its effects being used, Compiz still taxes the GPU and performance decreases. Compiz would be but a simple example, as is the most prominent application which uses AIGLX. AIGLX is (the way I understand it, anyway), but a framework and infrastructure for acceleration under X, so other applications might actually make use of it too.
So, the conclusion we drew off our discussion was that while Compiz-Fusion is much more eye-popping than Vista's visual effects, and while it also taxes less on system resources, it still does so, that even the most famous of GLX applications (glxgears) receives a heavy performance blow when run under Compiz/Beryl... just as reference, and having into account glxgears is NOT a valid benchmark, the FPSs in my current system go from 7500+ FPS [FX5900] to ~2500 FPS under Beryl... that means roughly a decrease in performance of about 66.67%. I'm sure as the GPU scales, the delta in performance decreases, and as such it may not be so much of a matter with higher end hardware, but for cases of commodity hardware this means you have to choose between effects or no effects if you want to run other 3D apps.
I wonder what effect will glucose and HW accelerated Cairo will have in the way we get our daily fix of eye-candy?
Vista and Compiz utilize for their visual effects the 3D pipelines, as they (contrary to OS X) do actually perform window transformations and other 3D effects, without taxing much the system's CPU(s). This however has the downside effect of decreasing in most cases the performance of 3D applications when the "fancy visual effects" are turned on, a trade off many of us gladly take (is not like you cannot turn the effects off for running games or other 3D applications in either OS). While discussing this, my friend and I pondered what would be possible solutions to retain full rendering speed when running dedicated 3D apps (i.e, full screen) with the desktop effects turned on. As many users can tell, 3D performance does suffer quite a bit when you have running Compiz-Fusion/Beryl in the background and you launch a game. Even if the desktop is not being rendered, or its effects being used, Compiz still taxes the GPU and performance decreases. Compiz would be but a simple example, as is the most prominent application which uses AIGLX. AIGLX is (the way I understand it, anyway), but a framework and infrastructure for acceleration under X, so other applications might actually make use of it too.
So, the conclusion we drew off our discussion was that while Compiz-Fusion is much more eye-popping than Vista's visual effects, and while it also taxes less on system resources, it still does so, that even the most famous of GLX applications (glxgears) receives a heavy performance blow when run under Compiz/Beryl... just as reference, and having into account glxgears is NOT a valid benchmark, the FPSs in my current system go from 7500+ FPS [FX5900] to ~2500 FPS under Beryl... that means roughly a decrease in performance of about 66.67%. I'm sure as the GPU scales, the delta in performance decreases, and as such it may not be so much of a matter with higher end hardware, but for cases of commodity hardware this means you have to choose between effects or no effects if you want to run other 3D apps.
I wonder what effect will glucose and HW accelerated Cairo will have in the way we get our daily fix of eye-candy?
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