wich cpu that will cost ad run bf3 in the best as posible in bydget 230$
The Phenom II X4 945 (if you can find it) will be the best you can do, and what I recommend. It will probably need a BIOS update before you can use it though, unless there's already an AM3 CPU in it. It'll be MUCH cheaper than $230 though, just not easy to find new. You'll probably have to go to eBay and get one used. Just make sure that it's the 95W version.