Step by Step Guid to Processor Lapping

[Rocks7ar]

Processor
Model: Intel Core 2 Quad Q6600
Stepping: B3
Frequency: 2400MHz
vCore: 1.35v

Cooling
Heat Sink: Thermalright IFX-14
Fans: Silverstone FM121 (x2)
Flow Direction: Push/Pull
Thermal Interface Material: Arctic Silver 5

Testing methodology
Load temperatures were taken after 15 minutes of four instances of Prime95 small TFTs.
Idle temperature readings were taken after 15 minutes of inactivity with no programs running.

Temperatures Before Lapping
Ambient: 22C
Load: 52C
Idle: 41C

Temperatures After Lapping
Load: 43C
Idle: 35C

Lapping Methodology

Materials
- Water
- Small piece of plate glass*
- 600 grit sandpaper
- 800 grit sandpaper
- 1000 grit sandpaper
- 1500 grit sandpaper
- 2000 grit sandpaper**

* Do not use glass intended for use in windows as it is usually not as flat as plate glass.
** 2000 grit sandpaper is optional but does help to add a perfect mirror finish.

Step One
Using a permanent marker, draw an "X" on the processor's IHS. This will allow you to more accurately reference your progress.

Step Two
Stretch a sheet of 600 grit sandpaper over your sheet of plate glass and tape it on either side to ensure it stays tight and flat against the glass.

Step Three
Place the processor with the IHS facing downwards onto the sandpaper but do not apply pressure. Allow the processor's own weight to press down on the sandpaper as it is distributed much more evenly that you can reproduce with your hands.

Step Four
Using back and forth motions, slide the processor along the sand paper stopping every 30 or passes to rotate it 90 degrees to the right. Continue this process for about 15 minutes.

Step Five
Once you have lapped for 15 minutes, lift the processor from the sand paper and use a wet paper towel to clean off all the metal dust from the IHS and apply a new sheet of 600 grit sandpaper.

Step Six
Continue lapping in the same fashion for another 15 minutes.

Step Seven
After 15 minutes lift the processor from the sandpaper and thoroughly clean the IHS. Once you are ready, apply a new sheet of sandpaper only this time use 800 grit.

Step Eight
Resume lapping the processor in the same fashion for another 15 minutes.

Step Nine
After 15 minutes lift the processor from the sandpaper repeat step seven but instead of 800 grit sandpaper, use the 1000 grit.

Step Ten
Continue this trend of lapping for 15 minutes, rinsing and switching to a higher grit sandpaper until you have lapped the processor with all five grits.

Step Eleven
Rinse the processor extremely thoroughly with 90% rubbing alcohol. Be sure to get enough of the alcohol under the IHS that it will wash out any metal debris that may have gotten in there. Do not worry, this will not affect your processor as there is not current running through it at this time. Just be sure to allow time for it to dry completely before using it again.

Step Eleven
Apply your favorite thermal interface material and pop it into your computer.

After 30 Minutes With 600 Grit
After 15 Minutes With 800 Grit
After 30 Minutes With 1000 Grit
After 15 Minutes With 1500 Grit
After Buffing With Arctic Silver 5

 

[ArchAngel777]

I did everything except for water and dousing it with alcohal... I refuse to douse it in alcohal... Something just doesn't seem right about it, even though it may be perfectly safe. Just me...

 

[SerpentRoyal]

Water will greatly improve surface finish and durability of the sandpaper.

 

[Billb2]

Originally posted by: SerpentRoyal
Water will greatly improve surface finish and durability of the sandpaper.

Kerosene works even better.

 

[Rocks7ar]

Is that a joke or does it really?

 

[ArchAngel777]

It does...

While true that water does help smooth it out better (slightly) I still would not go that route. Personal preference, I guess.

BTW - I did use water for 1500g, but not for the others. So, I guess I should say that I do use water, but only for the fine sanding and buffing aspect. Much like sanding a car down and buffing out the dirt in the paint.

I never heard of anyone buffing their chip with arctic silver, but seems like a decent idea after thinking about it.

 

[Rocks7ar]

It adds an extra shine because of the uber small abrasive particles.

 

[Avalon]

Very nice.

 

[rodrigu3]

makes sense to buff with the AS5... the little silver particles will get pushed into any remaining crevices - kind of like a scratch fix

 

[coreyb]

I run my Q6600 at 3.6GHz and it idles at 43 degrees and can go up to 60 degrees on full load. Would it be worth my time to lap?

 

[boglwe]

Originally posted by: coreyb
I run my Q6600 at 3.6GHz and it idles at 43 degrees and can go up to 60 degrees on full load. Would it be worth my time to lap?

Is that air cooled, and if so, what are you using to measure?



ALSO......... GREAT THREAD< THANKS A TON.

 

[boglwe]

BTW? After you rinse with Alcohol, how much time should i let it sit? I hate not having my baby in action. heh.

EDIT: where did you get that heatsink? Did you buff with AS5 with your finger?

 

[Capitalizt]

My experience with lapping is that you must lap BOTH the CPU and your heatsink to get any measurable results. After 90 minutes of lapping my deformed CPU to a perfecty flat (near-mirror) finish, I was disappointed to only get a 2C drop in temperatures. When I lapped the Zalman fan as well, temps went down another 5C.

Two perfectly flat surfaces and a super thin layer of arctic silver 5 (spread with a razorblade) = TEH WIN!

 

[Rocks7ar]

Originally posted by: coreyb
I run my Q6600 at 3.6GHz and it idles at 43 degrees and can go up to 60 degrees on full load. Would it be worth my time to lap?

Probably not. If you want to you may shave a few degrees off of your load but nothing noteworthy.

 

[Rocks7ar]

Originally posted by: boglwe
BTW? After you rinse with Alcohol, how much time should i let it sit? I hate not having my baby in action. heh.

EDIT: where did you get that heatsink? Did you buff with AS5 with your finger?

I usually let it site 15 minutes.

 

[Rocks7ar]

Originally posted by: Capitalizt
My experience with lapping is that you must lap BOTH the CPU and your heatsink to get any measurable results. After 90 minutes of lapping my deformed CPU to a perfecty flat (near-mirror) finish, I was disappointed to only get a 2C drop in temperatures. When I lapped the Zalman fan as well, temps went down another 5C.

Two perfectly flat surfaces and a super thin layer of arctic silver 5 (spread with a razorblade) = TEH WIN!

Agreed but the IFX-14 came lapped.

Razor blade method FTW!

 

[ArchAngel777]

Originally posted by: Capitalizt
My experience with lapping is that you must lap BOTH the CPU and your heatsink to get any measurable results. After 90 minutes of lapping my deformed CPU to a perfecty flat (near-mirror) finish, I was disappointed to only get a 2C drop in temperatures. When I lapped the Zalman fan as well, temps went down another 5C.

Two perfectly flat surfaces and a super thin layer of arctic silver 5 (spread with a razorblade) = TEH WIN!

I had planned on doing this when I get my new heatsink. The way that AS5 has it on their website doesn't seem right for a lapped CPU. It will work fine for concaved, though. It sends up being far too thick... If you have a lint free cloth, you could probably work the AS5 into the HeatSink, and CPU... Then just an extreme fine layer of AS5 and firmly plant. Well, that is my plan this evening when my Thermalright SI-128 SE comes in.

 

[ArchAngel777]

Originally posted by: coreyb
I run my Q6600 at 3.6GHz and it idles at 43 degrees and can go up to 60 degrees on full load. Would it be worth my time to lap?

It depends... Right now you already have wonderful temperatures... Additionally, if your temperatures are correct (speed fan is wrong, coretemp = real) then you might not gain a lot since your CPU is already running real cool.

I am guessing your CPU is a G0. At any rate, my B3 ran at 80c P95 load after 15 minutes with my Tuniq Tower. I lapped it and after 15 minutes of P95 it was 71c. So I gained a lot, but I suspect that was more due to a really bad IHS... If you are getting good temps right off the bat, then i'd venture to say that you have a really good IHS and wouldn't bother lapping it.

 

[Rocks7ar]

The razor blade spreading method is definitely the best. My favorite TIM is Liquid Metal Pro, it gives the best temps by far but ruins the mirror finish.

 

[Capitalizt]

If you decide to use a razor blade, be careful not to scratch the top of the CPU. I recommend you first spread the paste out using your finger inside a baggie. Once you have enough paste on top, use a "paint the fence" motion with the razorblade to smooth it out. Some extra paste will probably end up on the sides of the heat spreader when you do this, but it won't hurt anything. The idea is to get a paper-thin layer on top.

 

[coreyb]

Ok, I was thinking it wouldn't really be worth the effort to lap. I'm using coretemp to check temps and occasionally speedfan with a 15 degree offset to double check.

thanks for the replies! As much as I love good temps, the thought of taking my precious G0 out of its socket and rubbing it on sand paper just doesnt sit well even though I know its safe if you're careful.

 

[Rocks7ar]

CoreTemp = Correct
Speedfan = Bad

 

[cautery]

LOL!!! Yep, lapping the CPU AND heatsink is one of the best and cheapest ways to get major thermal transfer improvements... I wrote a similar article and posted it here what.... like or nine years ago? Glad to see that folks are still willing to do things like this...

FLAT and SMOOTH... Anything that increases the metal to metal contact between the CPU and sink; and reduces the amount/thickness of TIM required...

I bet I hand lapped 50 or more C300's back when DistributedNet was hot, and we build WarpCore.

 

[jw0ollard]

Nice guide. Will do this on my next build.

Question: How important is a mirror shine? Would the difference between your last step and a mirror finish give at least an extra 1-2C? Doubtful, but thought I'd ask.

 

[ArchAngel777]

Originally posted by: jw0ollard
Nice guide. Will do this on my next build.

Question: How important is a mirror shine? Would the difference between your last step and a mirror finish give at least an extra 1-2C? Doubtful, but thought I'd ask.

You will get two different answers from two intelligent people. That is a hotly contested item... Some believe mirror finish helps, others believe it hinders it slightly. Personally, I never look at the CPU, so I couldn't give a shit as long as it is flat. So, I just grind it down to 1500 a few times and call her done.