I use Ubuntu 9.04 for my non-gaming computing typically; I enjoy the increased customizability, and the terminal program included by default is infinitely better than Windows’s shitty cmd.exe. But one of the things that bugged me for a while is that my screen would intermittently flicker black; parts or all of it would just turn black for a fraction of a second and return to normal. I managed to figure that it was only happening when I had the Compiz window compositing manager running, but all the suggestions I was given failed to fix it. Eventually, I tracked it down to PowerMizer, a feature NVIDIA includes with its graphics cards in order to decrease power usage. It’s useful, but sometimes changing power settings on the graphics card can cause the screen to flicker. So I did some quick Googling, and found a fix that works by disabling it entirely. But this will increase power consumption and possibly cause your laptop to heat up (not dangerously so, but enough to be noticeable), so for completeness’s sake I recommend you try these steps first:
- Disable Compiz and use your system for a while; by doing so, you should prevent PowerMizer from having to switch the power supply by ensuring the load on your GFX card never passes a certain level. If it’s still flickering, something else is the culprit.
- Run Compiz with the –loose-binding option but not with –indirect-rendering. If you’re using fusion-icon, which I heavily recommend, you can right-click it and toggle these under “Compiz Options”. If you’re manually starting it, you’ll need to add/remove these switches to whatever process you use to start it.
- Open CompizConfig Settings Manager, and in the Workarounds settings, under Utility, enable Force Synchronization between X and GLX.
- If steps 2 or 3 worked, play around with those three settings until you find something that works for you. I personally enable loose binding due to the performance increase it gives me, but your mileage may vary.
If all else fails, read on.
