A 850 ofcourse can play BF3 MP on a 16-32 / 64 server. It'll depend on what settings you want to have and how powerful of a GPU you have. Although BF3 takes as much processing power as you can provide it; it won't completely smother any recent intel dual core in any meaningful way as long as you tone the settings down a bit.
Any LGA1155 Pentium is capable of doing that, just depends on your settings as lilotimz has stated.
What resolution are you playing your games at? This would also be a factor on how smooth your gameplay is