nikoli707 :
definitely get a 3gb vram or higher video card for sure... 2gb is not going to cut it at all for anything above 1080p... and even at 1080p it struggles in certain games.
It seems that vram is not much of a performance issue. Read this:
http://www.pugetsystems.com/labs/articles/Video-Card-Performance-2GB-vs-4GB-Memory-154/
iDieAlot1986 :
One monitor on ultra settings at 1080P w/ playable FPS= 7870
3 monitors on medium to high at 1080P w/ playable FPS= 7950 or 7970
If you will use triple monitor gaming, a single card short of a GTX690 type card will not do.
But, if you mean only to have three monitors attached, then the graphics card need be no stronger than for a single monitor.
The market is competitive.
You get fair value at every price point, excepting, perhaps the very top.
This chart is an approximate ranking of cards.
http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107-7.html
You probably can't detect the difference between tiers without a synthetic benchmark.
I suggest one buy the strongest single card your wallet and psu can support.. If your graphics card budget is >$800 or so, only then consider dual cards.