the 8150 is utter pants for gaming atm. it will likely remain so till the new consoles arrive and there multi threaded games get ported.
the 8350 is a different beast it will compete pretty well with the ivy bridge in most newer games when its overclocked to 4+ghz. it has much better single threaded performance and over all a better choice than what you currently have.
this is probably the only time i wont say buy a new gfx card because the old fx cpu bottleneck so badly you really need to sort that out first.