Anandtech: Overclocking Ivy Bridge.
My recommendation is that if you run an overclocked Sandy Bridge system right now, do not jump to Ivy Bridge. You may be severely disappointed by the overclocking performance. Ultimately, Ivy Bridge hates voltage. Moving the CPU speed up is not so bad in the case of temperatures and system power draw. What you need is the lowest voltage for the overclock you want. So when you overclock, be methodical.
Not terribly surprising. Smaller features mean less voltage tolerance before bad things happen.
Cheers,
Scott.
(Who is waiting to see what Apple offers at 22 nm...)