Looking for a post I posted I came across this article (not the right one):
Battlefield 3 Performance: 30+ Graphics Cards Tested http://games.slashdot.org/story/11/10/29/1922214/battlefield-3-performance-30-graphics-cards-tested
I know how to crash a system with any video card running BF3, Bold statement as it's not totally the video cards fault and a crash isn't always the result; but you will have a lot of problems until you reboot.
Running BF3 without pagefile.sys or disk cache, will crash or or severely cripple the OS.
After playing for a while you will be asked politely to quit BF3 as your running out of resources - windows 7 also request shutting down it's charm (DMV.exe) and other services.
Thing here is all the requests are behind the BF3 game screen, you'll start loosing control of any equipment your in, or other odd stuff pertaining to input.
I have 6 Gigs of ram and BF3 is the only application where a Pagefile is required, even Photoshop runs without one now.
Yet for all it's problems BF3 is a very enjoyable game that I play daily but now with a pagefile on a slow drive. My video card: EVGA GTX570