I'm going to get a new system with the Phenom II x4 940 which is only sold as boxed-version where I live (with a stock cooler). Someone proposed to get a Scythe Mugen 2 cooler, but I'm not really sure what the gain will be compared to the stock cooler.
First of all, I'm not really an overclocker, but since it will be easy with the Black Edition CPU I might overclock a bit in the future when the 3GHz quadcore is getting slow. Even then I won't be pushing for the limits. I have to shell out $45 extra for this non-stock cooler which seems a bit much if I don't really need it.
So basicly my question is, will the stock cooler be good enough for me assuming that somewhere in the future the processor *might* be overclocked from 3.0GHz to let's say 3.4Ghz or something along those lines?
The stock cooler should be sufficient, even with a mild overclock later. However, you may want to still pick-up some Arctic Silver 5 thermal grease for use with it. It's a small expense (~$6-9) for better heat transfer/cooling efficiency and typically reduces temps 2-5C over the stock stuff.
2-5C if you apply it perfectly, which beginners often don't. If you're aren't experienced or confident, I'd just use the pre-applied stuff. Zero chance of screwing that up. On the other hand, a nice tube of Arctic Silver will go a long way.
I don't care much for the Arctic Cooling Freezer...
I went with an Apack/Zerotherm ZEN-FZ120 on my Phenom II X3 720. I can get it to 3.725Ghz @ 1.425v and still don't see temps above 45C in Prime95 or Orthos, ever.
That's with a heating element (aka an HD4890 card) sitting below it.
It's pretty quiet, too, even at full speed.