(My rig isn't put together yet, and I may yet switch back to a single Pelt.)
Pelt cooling has many advantages, but requires a lot of careful details. It will allow you to cool a CPU beyond any other type of cooling.
The question: "How far will I be able to OC my CPU?" isn't easily answered. Most will tell you that it depends on the CPU you have, which batch it was made from, etc... then they'll tell you that it depends on all the other components (Mobo, ram, etc...)
In short, you can't pick a target speed for OC'ing a CPU. You just cool it down, and hope for the best. A pelt (aka TEC - Thermo electric couple) will allow you to OC better than water or air cooling.
Me, I'm targetting 166 FSB with the new Athlon 2200+, whenever it comes out. (or 33MHz above spec FSB). Anything else is just a bonus.
When setting up Pelt(s), you have to consider:
-isolating for condensation
-powering it
-cooling it
-mounting it
That's the basics, then there's the water-cooling aspect of it.
I've seen people OC an Athlon 2100+ (1.73 GHz) to as much as 2.2 GHz (stable???).
Once it's all setup, then you have to run some tests, start the burning in, and take measurements. The CPU temp will probably rise above freezing, under full load.
This is why I'm building a thermally controlled PSU for my pelt(s). That way, my rig will hold a CPU at a rock steady temperature, regardless of the load on it, and it will save energy in the process.
I'm not there yet...
