IMac 27" freezes when running 3D games

Question

Hi,
I tried looking for my issue using the search but haven't found it. So please apologize if I missed an existing thread.
I'm using a late 2009 27" inch iMac i5 (ATI Radeon HD 4850) with 10.8.1 installed.
Everything works fine so far but 3D games.I tried World of Warcraft and CounterStrike: Global Offensive. Either game causes my iMac to freeze 1-10 minutes after launch.
The screen freezes but the mouse pointer can still be moved. I even continue to hear the game sound and the teamspeak client in the background keeps working properly as well.
When I SSH into my iMac from my MacMini I can access the system jsut fine. If I then locate the task and kill it ("kill -9 <PID>"), the game sound dies, but the screen doesn't change.
The only way to get my iMac working properly again is by switching it off&on.
I tried to fix it by closing all open apps in the background - no joy.
I also repaired the permissions using the disk utility.
Any ideas?
Thanks,
Sven

Answer 1

I just reinstalled 10.8.1 from scratch after wiping the HDD. I also restored all my files from my time capsule.
After a fresh installation of Wow the behaviour now has slightly changed:
After the game crashes, the screen turns black. A couple of seconds later it turns white and after waiting another 5-10 sec. I get the OS message that my system has crashed and that the computer will reboot. And it does reboot
On the error report it reads:
panic(cpu 0 caller 0xffffff801b49dadb): "TLB invalidation IPI timeout: " "CPU(s) failed to respond to interrupts, unresponsive CPU bitmap: 0x8, NMIPI acks: orig: 0x0, now: 0x0"@/SourceCache/xnu/xnu-2050.9.2/osfmk/x86_64/pmap.c:2337
I can post the whole report if anybody is interested...
Thanks,
Sven