New clamp for PIV heatsink
 

Overclockers.com has an interesting article on an air cooled heatsink for the P4. You can read it here http://www.overclockers.com/articles506/

The basic idea is to increase the clamping pressure by 5 times more than the Athlon can handle. The higher pressure improves heat transfer to the heatsink. Clever bit of engineering in that the clamp doesn't require any tweaking to get the pressure right - you just flip two levers (at the same time?) and you've got 100 lbs of pressure on the die.

A big payoff in this solution is that the fan is so quiet, Joe Citarella's db meter couldn't read it. Joe's using a cheapo Ratshack meter that only goes down to 50 db but still....

A lot of folks have signed off on speed - the cpu's are plenty fast. What we want is a silent computer. Like the Mac cube but fast.

Pressure can make a world of difference. Just tightening the boltss on my Maze2 with pliers dropped temps ~4C, and thats only a few turns more then I could do with my bare hands.

this is why i opted for "wing-nuts" ... easier to get an even pressure and higher (or anyway that is what i think haven hade the time do test it yet)

the other thing to remember is that pelts are supposed to have a 300lbs/in pressure on them. surely a cpu would be great with that much pressure on it. Of course, we'd crack the core, so 22lbs/in or so is all we are allowed

22lbs/in for AMD only..
 

22lbs/in is all the Athlon allows .. the PIV will handle the 100 lbs/in. The PIV has some nice features - onboard thermometer, slow down circuitry if the chip gets too hot and now this - the ability to handle some hefty pressure. It's clear that Intel is shifting the rules of the game. We can't beat em on performance so we'll beat em on these nifty little extras.

At the last Intel Developer conference, Intel was showing off a PIV that was passively cooled. This is one area where I think they're spot on - trying to keep the noise level down. My ideal computer would be a 2ghz Athlon that was passively cooled.

you could do a passively cooled athlon, have a remotely located pump, pumping water back and forth to a huge body of water with a large radiator

Brad,
Having a pump makes it an active, not passive, cooler.

What I have in mind is either a heat pipe going into a large radiator like you have in mind or a tapered water block that uses convection to drive the water flow. Seems rather wasteful to not tap the 60+ watts from the cpu to cool the cpu.

by passive, I was referring to no fans, but yeah I get what you mean.

Heatpipes work well, but you still need to cool the hot end

This has been done before with pretty good results.

Heat Pipe 101

Check out installment 2.2 as well.

Heat pipe been done
 

Yeah, he did a nice job but again, he had to resort to fans to cool the condenser.

What I'm referring to is a completely passive solution - no motors anywhere. I'm not looking to overclock my machine, I just don't want to hear it while I work.

overclockers has a roundup of p4 heatsinks, check out the mcx462 beating everyone again