Muad'dib

To the best of my knowledge, the whole point of thermal compound is to fill in the gaps between the HS and the CPU. Any surface imperfections will be filled with a media to conduct the heat generated by the CPU to the heat sink and away from the CPU.

From what I know about lapping metal, you make the surface smooth on a microscopic level by properly lapping something, and thus, remove the need for any media to fill in the gaps.

Thermal paste cannot conduct heat as good as metal. In theory, if the two surfaces are smooth, any thermal paste will INSULATE the CPU.

From what I read about using AS5, it should be scraped with a credit card or something so there is no excess. If you lap something smooth, then scrape the AS5, you will have nothing left on he part, correct?

Am I missing something? I really think this whole lapping thing is a scam. How much of a gain are you guys seeing? I can see hitting something a couple of times to make it flat so it seats good, but $13 plus shipping for sandpaper and a piece of glass is a huge rip off IMO if it only gains you a degree or 2.

So, hit me up with some data. I would like to know if its really worth it before I spend too much time on it.

kidwolf909

Lapping also helps to FLATTEN the surface, which is more important than smooth-ness. A flat surface provides more contact area with the CPU IHS, allowing for better thermal conductivity. By lapping my BT and IHS, I lost 8-10C AVERAGE off my load temps, 3-5C off idle temps.

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Dezixn

Flatness first
Smoothness / Mirror finish second.

Now theoretically if you got it EXTREMELY flat and EXTREMELY smooth there would be no need for TIM. The informationator sorta did this... But it would still cool better with TIM.

You do have sort of a point though. Why do you think we use so little AS5 on lapped components, because any more will insulate said components.

Oh and sand paper is $6 shipped lol.
I actually got a 9-10c drop on load temps. 2C or so can be attributed to proper AS5 application vs the old crappy application though.

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Bal3Wolf

With my lapped pd and zalman 9500 when i clock at 4400 i dont go pass 56c. When i waset lapped i hit 65c at that speed. Now i can run 4580 and still stay close to 58-63c.

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[S]teel [R]eign

Some cpus and heatsinks are concave or convex, infact so concave or convex that you can actually roll a razorblade over some of the curves a few degrees, this causes the heatsink/ihs to have bad contact with the rest of the hsf/ihs. Lapping attempts to remedy this. Usually you will only see about 4-5c gains if you lap HSF + your heatsink. However , if yours is so convex that you can curve it a few degrees and is not a good chip (doesnt oc high) i think you should rma it so that you can have a better chance of getting a good chip.

Muad'dib

Thanks for the replys!

This is the info I was looking for. Flatness is what I was thinking was more the point.

Any of you guys have access to a lapping plate and clover compound? the compoind you can get at the auto parts store, but the plate may be a bit harder/more expensive, but much better suited to the job.

After its lapped, Im thinking some jewelers rouge may even make the surface smooth enough to be metal to metal.

It may be worth a try