What are you going to be doing with this computer, gaming? Ivy Bridges is only a little better in performance the slight increase probably wouldn't even be noticable in most games. The biggest change between Ivy Bridges and Sandy Bridges is the shrinking of the die and better integrated graphics. Ivy Bridges does tend to run hotter than Sandy Bridges because Intel switched to thermal paste to solder the IHS to the chip instead of fluxless solder. Both can still be heavily overclocked but the Ivy Bridges might not get to the same level as a Sandy Bridge CPU because of the heat problem. IMO there isn't enough of a performance increase to make it worth getting Ivy Bridges.
ok I'll go to a 2500k, thanks for the tips
And yes this is a purely gaming pc, aside from random stuff like MS office work for school, youtube, fb, etc...
Also I'll be overclocking it with an h100 push/pull
There is no sense in upgrading to a 3570K from a 2500K.
But, for a new gaming build, I would go with the 3570K at anywhere near equal price.
The 3570K is faster, by about 5% on a clock for clock basis. Under normal operation, it runs cooler.
When overclocked to conservative levels, say 4.3 there is no heat issue. The problem comes with very aggressive maximum overclocks that require big voltage increases.
For the gamer, the graphics card is more important once you reach the 4.0 level.