Need a very small and powerfull HSF

If you don't have room to stick a decent cooler in there, then you have to either get a case with sufficient room, or move the heat elsewhere before dissipating it (i.e. watercooling).

What's your system temps? The cpu won't really get any cooler than the temperature of the air being blown over it. Ensure your case has good airflow.

Finally, you could get some silly tornado fan with ridiculously high airflow which will help, but will be LOUD.

Basically, small systems should never be performance ones. At least not <i>quiet</i> ones.

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Should've asked this sooner, but do you know if your processor is a Northwood or a Prescott?

If it's a scotty, your temps are already about at low as you'll realistically get them if you're limited by a small case.

I'm not familiar enough personally with watercooling to recommend anything, but you'll no doubt find best results are from buying separate parts rather than a kit. If you want the <i>system</i> to remain small, you're probably out of luck though, as you'll almost certainly need an external radiator which will be both ugly and take up space.

Do you <i>really</i> need a small system? I like a reasonably sized one, since I usually stick it under the desk and rest my feet on it .

A half-decent MicroATX tower will be wide enough to accommodate a decent air cooler, and will cost a lot less.

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