I'm sure a similar question has been asked, but would a computer with 2 GTX 470 cards run any differently than a computer with one? I want to build a PC for video )editing(HD short films, and learning After Effects) and some gaming (MMO, particularly Guild Wars 2). That's all
There would be no performance difference (Premiere doesn't use SLI or anything like that), but you could potentially run three monitors if you wanted to.
To add to Colins remark:
and will run much hotter, louder and require a massive PSU (think 1200+W) plus additional modding to the cooling to keep temps in check.
and to add to it it wont help gaming any if you play MMOs
so unless you just want bragging rights ther is no point to dual video cards
you can get a 3rd preview monitor with w decklink intensity or other capture cards
or a cheap video card
better to buy a single 580