So there's currently a little sale going on at Newegg. I've been slowly purchasing components for my new PC and am torn between which CPU I should get here. On sale, the Sandy Bridge is $279.99, which is $10 cheaper than the Ivy Bridge (which I originally picked out).
Sandy Bridge: http://www.newegg.com/Product/Product.a ... 6819115229
Ivy Bridge: http://www.newegg.com/Product/Product.a ... 6819116502
The Sandy Bridge has better base speed (3.6 ghz) than the Ivy Bridge (3.4 ghz), but the Ivy Bridge has a better turbo boost (4.9 ghz) than the Sandy Bridge (4.8 ghz). The Sandy Bridge also has 10mb of L3 cache while the Ivy Bridge only has 8mb of L3 cache. And of course, Ivy Bridge is 22 nm and 77 watts, while the Sandy Bridge is 32 nm and 130 watts.
The Sandy Bridge uses LGA 2011, and the Ivy Bridge uses LGA 1155. I would have to pick out a new motherboard that supports LGA 2011 if I wanted the Sandy Bridge.
So basically, how important to gaming is L3 Cache (10 mb vs. 8 mb), the base operating frequency (3.6 ghz vs. 3.4 ghz), the manufacturing tech (22 nm vs. 32 nm), and the thermal design power (77 watts vs. 130 watts). These are the main differences between both processors that I've noticed when observing the specs on them. I don't know all the critical details about Ivy Bridge, just that it's supposed to be better.