Primus' vsync seems to often cause severe latency. Disabling it (vblank_mode=0 primusrun %command%) solves this issue but causes tearing as you mentioned.

It isn't a fix but I suggest trying to enable vsync in the application or game. This is usually fairly easy to do in engines like Source and Unreal and works much better than Primus' vsync. Vsync and an FPS limit of 120 works well in most scenarios.

I am not too sure about that crash. Maybe it is just some Linux bug? I also have no idea what pathmatch is. It was something recently added to the HL2 engine startup scripts. I the lines in my scripts just to be sure.

Hello, I have deleted the previous duplicates.

I do believe you are overcomplicating things a bit, however, the crash is related to using LD_PRELOAD

This thread has a few working examples as well as some information on the LD_PRELOAD crash.

Do you have the "$LD_LIBRARY_PATH" part in the full command? Leaving out that specific part will cause the sound to stop functioning in some games.

You can check FPS by opening the console (key: ~)(must be enabled in options) and entering cl_showfps 1

Yes, it is typed as-is. Question, does 'optirun glxspheres' work? And what distribution are you using?

Hello! The file hl2.sh is overwritten each time the game is launched. Steam, however, has implemented Optimus support. This can be activated by:

Right click on TF2 in your library
Click Properties
Click Set Launch Options
If you only have optirun, enter:
OR, If you have primusrun enter:

Enjoy!

Huh... Based on that error message the Unreal Engine is trying to launch in 1080p instead of 1366x768. Can you post the output of your Killing Floor config file? (feel free to use pastebin) I believe it might be in ~/killingfloor/system/killingfloor.ini or something similar. I am not on a computer with it installed at the moment so you may have to hunt for it a bit.

Next, can you post TF2's error log and finally does 'optirun glxspheres' work?

Oh and are you using a version of Bumblebee you compiled yourself or one from the PPA?

Does optirun work?

Thanks! Added!