I3 3220 is best 1) new generation cpu and slight faster.2)comes with hd 2500 grahics while 2120 has hd 2000.3)support upto 1600mhz ram while 1333mhz in 2120.4)55w power consumption while 65w with 2120.This clearly shows i3 3220 is better than 2120.
Psssh Then I don't know why I am answering your question! Seems like you know more than me anyways! Just saying that it may make the difference if you plan on switching out MOBOs and possibly using Xfire or SLI. Or you know.. go crazy, ditch your case, and turn your PC into a pile of wire, GPUs and watercooling system(s) (the tubing must change colours).