Lapping your CPU Guide

[dttuner]

Originally Posted by Yellowhello

1. No, I did it all dry.
2. Hmm, I'd recommend lapping both the HSF and the CPU in that case.
3. I wrote this a while ago, and I kinda forget... sorry.

Thank you!
.

[Parker]

Originally Posted by dttuner

Couple Questions:

1 - Do you moisten the sandpaper at all, since it's wet/dry sandpaper?

2 - If my HSF is very convex, to the point where only the very center of the HSF touches the CPU... would this work for me? Will it remove enough metal?

3 - How long did stage 1 take you (400 grit) ?

Thanks! Great guide!

I used Nate's lapping guide when I lapped my QX6700, worked really well!
The only things I did differently was completely wet the sandpaper, just run the whole piece of sandpaper under some water, shake it off so that it juts leaves the sandpaper damp.
And then I only went up to 800-grit, past that there isn't any more performance increase you can get, and in fact if you go to far like 2500 grit it "can" hinder performance.

Also, NEVER polish a CPU chip, nobody cares how shiny your proc is, and you won't even see it since it's going to be under a HS.

I used a 1/2" thick piece of tempered glass that my dad just "happened" to have...

On the 400 grit, it took me about 10 minutes until the only thing you saw on the chip was copper, then I moved up to 800 grit for another maybe 8 minutes.....

Lapping is easier than people say it is, and it's not really dangerous if you know what your doing. I was surprised myself at how easy it was....
The only thing I recommend is to NOT put a ton of pressure on the chip when your running it down the sandpaper, you could mess up the whole lap if you have to much pressure on one corner or something....
And try not to press down on the center area of the chip where the little soldered pieces are, you could damage those that way.

Just my 2 cents, I know you were asking Nate this question, not Parker... but I thought I'd chime in on my experience and what I learned in lapping.

~Parker

[dttuner]

Question: I have my Ultra-120 HSF which I need to lap, bigtime.
What I mean by bigtime is, it seems to practically come to a point in the center (exageration. Can't be seen with the eye)

Since it's so clunky and big... should I consider putting it on the table, and using some kind of belt sander instead?
Since this is not a CPU, there's less risk.
Where would I find such a power tool anyways?
.

[Parker]

Don't try a power tool.

Just do it like it was a CPU chip, hold your hand under the HS fins ontop of the base of the HS. And just run it down the sandpaper pushing it down flat.

[Capper]

I'm honestly 100% against things like lapping and removing IHS'.

When lapping, you risk ruining the processor with moisture or metal flakes getting under the IHS. You also risk lapping it unevenly, which is very hard, and borderline impossible to recover from.

Honestly, the temperature difference can range from 1-7C, which might sound impressive, but once you take into consideration the max operating temperature and the overall performance....its just not worth the risk.

As to the CPU cooler, its under warranty, I'd recommend sending it in for a replacement if its defective.

[Parker]

Originally Posted by Capper

I'm honestly 100% against things like lapping and removing IHS'.

When lapping, you risk ruining the processor with moisture or metal flakes getting under the IHS. You also risk lapping it unevenly, which is very hard, and borderline impossible to recover from.

Honestly, the temperature difference can range from 1-7C, which might sound impressive, but once you take into consideration the max operating temperature and the overall performance....its just not worth the risk.

That is your opinion, and I'm not against that.
But IMO, lapping is well worth it.

If you have a good piece of tempered glass and have the chip pressured evenly with your fingers, it won't be lapped at an angle.

Tho most performance difference in lapping is Load temps, my load temps dropped about 10c from lapping, Idle temps went down about 4c.
And IMO, 10c is a LOT.

Just my 2cents on lapping.

Edit: the only way I wouldn't recommend lapping is if:

1. Your worried about warranty
2. Your chip/HS is already pretty flat (you can find out by putting a straight edge on top of the chip)

As to the CPU cooler, its under warranty, I'd recommend sending it in for a replacement if its defective.

I have never seen a TRUE with a completely flat bottom.
People complain about it all the time, but the company won't replace them, because thats how they all are.
But if you can get it replaced however, the one you get back I can almost 100% guarantee that it will not be flat either.

Lapping is the only way to solve that problem. And thats what I intend to do once my black TRUE comes in.

Just my 2cents on TRUE's.