buying a new comp what would you suggest

[Anaximander]

Don't go for an AMD CPU if you have money to spend. The chips are physically larger, develop more heat, consume more power and have drastically lower performance pr. core; which is still what matters in almost all games. AMD CPU technology is a lot less sophisticated than the i-series, and the i-series is only priced marginally higher than similar-ish AMD CPU's. Moreover you won't get PCI-E 3.0 with an AMD processor. I'll wager my money that you'll get better perfomance in BF3 on a high-end i5 or i7 and a matching PCI-E 3.0 card than you will on any similarly priced AMD CPU, even though that particular game is one of the few that can take advantage of 6 or 8 "true" cores of an AMD CPU.

Check that Guide from Tom's Hardware, they know their stuff.

And you probably will be playing BF4 when the hype has peaked and the BF3 servers start shutting down, just sayin' It's impossible to like EA, but the BF series is the best shooter series there is.