1.575v

The next big speed milestone took 1.575v to achieve with true stability. This being 2.3Ghz

I'm thinking about using this speed since it still stays rather cool. I'll probably use this when I put a bigger heatsink on and a nice quiet 80mm fan.

1.8v

This is the end of the line for a cheap heatsink. Under 100% load it gets a bit hotter than I'd like to use.

Conclusion:

Of course I could have gone higher with better cooling, but with how much more heat is produced by increasing the voltages I want to stick with a very cool running chip. Also my whole point behind this article is showing it with "free cooling" since this was a heatsink I never would have used had it not been for this nice and cool running chip.