What does it matter stock or aftermarket? Everyone says core 2 duo is less hot cuz its 65watts. That's the only differemce. I mean its faster and everything. So if not watts then what?

Aftermarket coolers generally cool much better, and therefor keep your processor cooler. The big difference between the C2D and the Pentium is the architecture. The Core 2 Duo uses the new Core architecture, which does much more work per clock than the Pentium 4 Netburst. Also, its not the watts that make the difference. what it is is, most Pentium 4s (the prescott for example) are made on the .090um or 90nm process, which is how big the transistors inside are. the smaller they are, the cooler they run. the 65nm process uses much less power and puts out much less heat than the inefficient 90nm process.

But ceder mill p4 is also 65mm so should it use less power and cool better?

yes. so no matter which Cedar mill you get, it will use the 65nm process.

Pentium 4 631+ 3GHz Socket 775 LGA775 SL9KG !NIB! - (eBay item 200180487508 end time Dec-09-07 13:51:07 PST)

Well I won this ebay auction. It's not ceder mill. But its supported according to manufacture link. It is 65mm. And he emailed me and it does say SL9KG on top of the cpu. That is the lower 65w model. So I'll give it a try and see.

actually that is a Cedar Mill. any Pentium ending with 6x1 is a Cedar Mill Core. but good luck, i hope it works out for you

I thought that was presler. What is presler then? Which ones? Only the dual core ones?