2011 27 iMac 6970m dying?

I fear i know the answer, but maybe someone here has more knowledge.
I started seeing some really odd distortions during Starcraft 2, and now the game is not playable. I can not recreate this in OSX ML, or watching movies, or any other apps, but during other games such as SWKOR i get the same problem.

27 imac, 3.4 i7, 16gb ram
6970m 2gb option. osx 10.8.2

http://www.flickr.com/photos/90600859@N06/8228960224

http://www.flickr.com/photos/90600859@N06/8227892937

If the video card is bad... does my SSD installation affect my applecare? I did not take off any "warranty void if removed" stickers, but curious if anyone else who has added or modified disc has tried to use applecare after.

thanks!

added a Samsung SSD behind optical

Forgot to mention, The iMac turned off two different times.

One of the times i heard a distinct "pop", however, it powered itself right back up, without me touching it