Well, i was playing with my wolfdale until i killed it.

This is a dualcore mind you, so let me tell you how badly the voltage scales.

On my Wolfdale, i was able to pull about 4.0ghz @ 1.4Vcore and have it hold prime95 for hours.

4.1ghz took about 1.47Vcore
4.2ghz took about 1.51Vcore
4.3ghz took 1.57Vcore
4.4ghz not possible
4.5ghz i wished but not possible.

Chip died after 1 month being loaded @ 1.57Vcore 24/7. :T

Higher overclocks are just too hard, the voltage doesnt scale as nicely as you wished it was.