Ugh. I think I need to RMA my 770GTX as well but I'm not sure I want to after reading all of this. It randomly locks up during WoW and nothing seems to be resolving it. Weird thing is that it doesn't lock up in any other game.
Should have just kept my 5870, the tank that it was. Not one hiccup in the 5 years I had it.
You should still RMA it. Here is why:
1. If your 770 dies, you'll need to spend $250+ out of pocket for a new card such as 290/970.
2. Once you get an RMAed 770, test it and if it works well, sell it immediately. As I said, there will probably be users interested in 770 level of performance for $160-170 or to SLI one.
So you don't have to be out of a card for all this time, just grab an
R9 290 Tri-X with 4 free games for $250. Sell the games if you want and you just got yourself a very cheap upgrade as it should be relatively easy to sell a 770 from the RMA for $160-170. With this option, you get 2 years of warranty with the Tri-X but with your RMAed 770 you are also back to no warranty.
Essentially, the small cost to upgrade gives you 2 year warranty, more performance, double the VRAM. If you play a lot of TWIMTBP and Blizzard titles, it might be worth it to get a 970 (esp. for Unity and FC4).