Depends how you stick them in your mobo. If you have a triple SLI/Crossfire mobo then running two cards would be fine. Running 3 would be risky depending on the mobo. Running a single card though, I don't think they have too much difference in life span.
Any electronics that run at high temperatures has a shorter life span now anyway. Solder failure is quite high since most companies stopped using lead based solder, so the solder won't last as long. (PS3 is a big example.)
Originally Posted by Henreh
Then let's see how the 6990 compares :O. I doubt anyone of us can afford either :P
Quite true. Lol I'm debating whether to get a GTX460 or something weaker. y so poor