what's the deal with lapping?

[coreyb]

Hi,

I'm putting together my new computer this week and was curious about this whole lapping thing. Is it neccessary? It's my first build and I'm going to be overclocking, however, I'm not too confident about it all.

Any advice or comments are appreciated.

 

[ethugholla]

In my opinion, not really necessary.

It reduces temperatures by a few degrees, and unless you're going to be doing HEAVY overclocking, don't do it.

I also could be saying this because I was too scared to lap my own processor.

I'm curious to see what other people do.

 

[gwai lo]

It's not necessary, but sometimes people get horribly convex/concave processors/heatsinks...and lapping can help out a lot in those cases. That's where those "lapping dropped my temps 10C" threads come from.

 

[Zardnok]

Get a straight razor blade and run the blade edge along the top of your chip while looking at it from the side. See how much light shows between the blade and the top of the chip. If you can see lots of light, you likely need to lap it. If there is not much light showing, you are likely fine.

Lapping is not as hard or as scary as some people make it seem. Basically you just use increasing grades of sandpaper to make it perfectly smooth.

 

[firewolfsm]

I lost 5C, and since with the stock cooler, heat is limiting my OC the most I could raise it from 2.7GHz to 2.9

 

[Aharami]

I plan on lapping my cooler. not my CPU though.

 

[coreyb]

well that clears things up nicely for me, thanks guys.

 

[jeffw2767602]

Thermalright has poor quality control and most 120 Extremes need to be lapped.

 

[Nickel020]

Well lapping certainly helps, but I'd lap the heatsink first (in fact I did ). My temp dropped ~11C after lapping my Infinty, and another 1-2C after lapping the CPU as well.
Use a razor blade or better a straight edge to check the CPU and heatsink first though, it's not always necessary.

 

[SniperDaws]

Does anyone know of a really good step by step guide with pics and stuff for a never done before lapper like me ?

im ordering a tuniq tower on tuesday.

 

[Griswold]

From the comments section of the Thermalright Ultima-90 review here at AT. This is what Wesley Fink had to say about concave/convex CPUs and HSFs:

Thermalright is not alone in advocating convex bases. Swiftech has moved from promoting flat, mirror-finish bases to convex bases with a finish not as good. They call them their bow base and claim 2 to 4C better performance with the "bow".

Engineers have found that the convex base (fat center) mates tighter in the area of the CPU under the cap. Also Intel manufactures caps that are not flat by design - conncave, convex, and wave designs are all used in certain processors. Research shows the convex cooler base mates best with any of these 3 Intel cap types.

The point is this is not a marketing story, as you will see as we go into water-cooling in more detail. Lapping a convex base Thermalright can DROP performance by 2 to 4C.

With that in mind, lapping will most likely do more harm than good, especially if you only lap the HSF and not the (Intel) CPU.

I believe a truly rough surface on the HSF is the only case when some mild lapping is required. Then again, I'd probably just return that HSF and stick to a different brand.

 

[Acanthus]

Id RMA a cpu before lapping it, if it was casuing high temps from a uneven heatspreader.

That being said, ive built over 1000 PCs in my life and never had an issue with temps due to this.

 

[Griswold]

Originally posted by: Acanthus
Id RMA a cpu before lapping it, if it was casuing high temps from a uneven heatspreader.

That being said, ive built over 1000 PCs in my life and never had an issue with temps due to this.

I doubt one can RMA a CPU for that reason. They're apparently designed to be concave - read above.

 

[Acanthus]

Originally posted by: Griswold

Originally posted by: Acanthus
Id RMA a cpu before lapping it, if it was casuing high temps from a uneven heatspreader.

That being said, ive built over 1000 PCs in my life and never had an issue with temps due to this.

I doubt one can RMA a CPU for that reason. They're apparently designed to be concave - read above.

 

[Capitalizt]

One flat surface and one unflat surface = uneven contact = waste of time

If you are going to lap, you need to do BOTH the CPU and heatsink to get results.