ATI driver - Performance in 3D games is several times lower than in Windows

Problems with the ATI driver have always been a main stopper in using OpenSuse, and still are due to a new issue I recently discovered. I use the open-source ATI drivers which come per-installed with OpenSuse. Although with my latest video card they finally work (and desktop effects show too) I discovered the frame rate in games is twice lower than in Windows. The game I noticed this with is the Nexuiz / Xonotic FPS (open source Quake-based project). In places where I have 100FPS in Windows I get 50 in Linux and so on, with the same graphical settings. Years ago I tried Unreal Tournament 2004, and although it started up I again remember performance was unplayable. From my experience, this suggests there’s a problem with the default configuration of the ATI driver.

I asked on IRC some time back, and the answer I got was surprising at least. Someone said “the default ATI driver is under-clocked so if someone burns their video card the team doesn’t get blamed”. I hope this isn’t true, since it wouldn’t make any sense to clocking it under the speed used by the Windows driver. I tried installing the proprietary driver as well for my distro, but that causes it to stop working entirely (no more desktop effects and 3D games have corrupt graphics at even worse performance). The official ATI drivers for Linux are known to be generally broken, so I’m sticking with the open-source ones unless there’s a good reason not to. Apart from this everything works well… but this issue keeps me from playing any games, and yet again makes me feel unsafe about starting a life in Linux after a whole Windows existence.

Does anyone know why games are times slower than in Windows, and what can be safely tweaked to fix this problem? My video card is a Radeon HD 6870 from Gigabyte and I’m using OpenSuse 12.1 64bit with KDE.

My issue has been fixed. It’s because I was using the fglrx / mesa driver, which I thought is the open source driver. I installed the actual open-source ATI driver from the geeko repository as explained here and now all of my games run at the same performance as in Windows (plus I have Catalyst Control Center). Been years since I’ve been trying to fix this, and now it works at last (previously that page gave me a bad driver, but that was months ago). With the fglrx one, I had both some crashes and all games were limited to 60FPS… but now my ATI card works perfectly under OpenSuse :slight_smile: