You know what really grinds my glxgears?

The glxgears utility is often mentioned in conjunction with testing OpenGL functionality. If you’ve never encountered it before (and indeed even if you have) it renders three cogs spinning in a way that is relatively pleasing to the eye. It also emits FPS data to stdout, but since most configurations lock framerate to the monitor’s refresh rate (so-called vsync) this generally just displays something very close to 60fps. It doesn’t take much GPU (or even CPU power, relatively speaking) to maintain this refresh rate nowadays, so unless you like cogs glxgears has dubious benchmarking value. However, if you’re using drivers built on the Gallium framework (ie, Nouveau or AMD’s open source drivers, not Intel or proprietary drivers) you can use glxgears to test a little-known feature, the Gallium Head Up Display (HUD).

GALLIUM_ HUD =" fps,cpu+cpu0+c pu 1:100; V RAM-usage; ps- invocations, primitivesgen era ted”glxg ears

You’ll get a nice Fraps- style overlay – Steam Settings offers a basic In-Game > FPS counter too – showing FPS, CPU and VRAM usage, among other things. This can be customised and works with any OpenGL program, including Steam. (Start Steam from the command line, setting the GALLIUM_HUD variable there. It draws all over the Steam client, but you won’t see that once the game starts and it’s much easier than figuring out how to start games from the command line). For more details set the environment variable to .