[Scott_Arm]

So, I used to play some games under OSX and it seem to run pretty well. I played through a good chunk of Portal 2 and could get it running well enough for my liking. I downloaded Dungeon Defenders the other night for OSX and it was running absolutely horribly. So I turned the graphics options down to low and set the resolution to 800 x 600, and it was the same mess. I thought that was weird, so I tried Left 4 Dead 2 and Portal 2. They ran very poorly. My next step was to install Dungeon Defenders in Windows 7 (boot camp, dual boot). I can run it on "high" graphics at 1280 x 800. Just installing Portal 2 to check it out.

I know OSX's OpenGL performance is not great relative to DirectX performance in Windows for pretty much every game, but it wasn't this much worse before. I can't figure out if it was the OS upgrade to Lion that did me in, or what. Any recommendations on what I can do to try to fix this, short of a reinstall? If I were to reinstall, can I create a Lion disc from the App store, or do I have to install from my Snow Leopard disc and then do the Lion upgrade from App Store?

My laptop does seem to have a particularly bad heat problem. In Windows it'll shut itself off if I run a game. Is it possible OSX is doing some kind of dynamic under-clock adjustment to keep itself from frying? Seems unlikely, but I've never seen my Mac get so hot that it shut down under OSX.

[Scott_Arm]

Ripped my laptop apart and found the fans were all clogged with dust and cat hair. Cleaned it all out and gaming under OSX has improved drastically. So, does Apple do some dynamic clock adjustments to prevent the CPU/GPU from killing itself? In windows I didn't seem to lose any performance, but the thing would bake until it shut itself off.

[Arwin]

Most systems do. Your PC environment is the faulty one in this case, probably not configured right.

[Grall]

The people in the middle ages were right - cats really are of the devil.

...Or well, at least their hairs are.