I've found that certain older games, ported to the Mac..Doom and Quake are two, will not run properly with auto switching enabled in system / preferences energy saver.
If you have this issue, just untick the box....The games will then run fine. Even forcing the discrete card in GFX won't fix the issue. I've found it to be most prominent on my MBP 17" The iMac seems unaffected, and I don't game on my Air.
If you have this issue, just untick the box....The games will then run fine. Even forcing the discrete card in GFX won't fix the issue. I've found it to be most prominent on my MBP 17" The iMac seems unaffected, and I don't game on my Air.