Originally Posted by jason387
Will the performance of the core i5 650 equal that of the core i3 3220?
No, unless you OC the i5. Also i just would not pick any i5 6xx's. They are simply i3's with Turbo, which is useless if you OC. In fact, my own i3 is the very same as that i5
, putting aside turbo, AES and TPM support.
Ivy bridge has a ~25% advantage over any Nehalem/Clarkdale CPU. What makes those old CPU's still shine against modern i3 is OCing capabilities. Any Clarkie i3 worth it´s salt can get to 4 GHz or more. I bet my own i3 is faster than any Sandy/Ivy CPU's, outside of AES applications. Obviously it eats way more power and emits a whallop more heat though, it's a given considering the high OC.
I would just pick an i5-750 or something, hell, even an i7 860/870/875k/880 would be better than any Sandy/Ivy i3, just because of the core amount. The downside, as i said before, is that Socket 1156 is a "dead" socket. While awesome and powerful (just like socket 775) no more upgrades will be launched for it, so it would be a better option to jump into a 1155 socket, or touch it up and wait for Haswell if you plan to switch sides.
I would switch instead to AM3+ CPU's. AMD will not be phasing out that socket for a while, so you would be able to upgrade as long as you get a good motherboard.