DH Guide: Lapping a Heatsink

DPGX

I finally got around to giving this a shot on my Coolermaster Jet 4 and I cant believe how nicely the surface came out It does a pretty good job of cooling although a bit loud at top fan speed. I did notice reasonable temperature drops, although I hadnt used it much since I switched systems and switched back to Intel again.
Mike

aboyandhisblob

a great help

nbacrazy

nice guide

a72cutlas

Just discovered this site/forum and so far have found it very informative so far. I just have 1 question RE: the lapping guide. I've seen in other places that you shouldn't use rubbing(Isopropyl) alchohol or nail polish remover because it will leave contaminants behind. Can you comment on this?

I'm interested because I have a ZALMAN CNPS7000B-AlCu CPU HSF that has been used on a AMD64 3200+ running stock. My temps have been 37-39C at idle, and I'm about to upgrade to a 4400+ which I plan to OC. I want to keep temps down as far as possible so I'm wondering if lapping will help me or is the Zalman money from the start?

Once again great guide and site.

The_Neon_Cowboy

the people that make Arctic silver also sell a cleaning solution.

But the stronger version (ones like 70% ) the one is more is you want,
the one thats more alcohol and its cheap, and you shoudn' really have
to worry about residue.

__________________

Partizan

I just bought an AMD X2 +3800 and running it currently at 2500 MHz at 1.300V (default is 1.350V). I am using an Arctic Cooling Freezer 64 Pro. It never crossed my mind I should lap it. But I probably will.

With my old AMD stock cooler which I lapped for my Opteron 144, I actually managed to rip out my CPU twice. Thankfully no pins were bend or broken.


I used a similar technique as stated in the guide, the only difference I made was that I used circular motion. It came out real shiny.

I am wondering if I should even lap the IHS of my CPU, because it doesn't look flat:



But I will lap away the AMD markings with serial number

Any suggestions?


Regards, Partizan

__________________

rolerzzz

Hi! I own zalman cnps9700-nt CPU cooler. It's heatsink base was perfectly polished. But while mounting it on my cpu I made many half and quarter hair(width) sized scratches all over it, I can feel them with my nail. Can that affect my CPU temperatures? Is it worth lapping it. It would be my firsth time.

cozumel

Hi rolerzzz and welcome to DH.

The less flat the surfaces of the CPU and Heatsink the less contact area. This reduces the amount of heat that can be taken away from the CPU. You ideally want totally flat surfaces - so yes, the scratches may well effect temps.

I take it you bought the zalman to improve cooling. Many 'techies' will automatically lap their coolers when upgrading to ensure maximum efficiency. If you've accidentally scratched it then its effectiveness will have been reduced.

If your load temps are cool then maybe its not worth doing (lapping). If the load temps are higher and you're looking at overclocking then its probably a good idea.

It's up to you whether you want to do it or not.

__________________

The_Neon_Cowboy

Pictures would speak louder then words!

yes, that can effect CPU temperatures, as the closer the contact the better the transfer of heat but thermal paste off sets that a little.

weather to lap it or not is up to you! there is expense and time involved, as well as a
risk of makeing mistakes. sure lapping it would be a good idea.

__________________

rolerzzz

Here are some images:
here is all heatsink+fan photo
here you can see the scratches all over th e heatsink base
here you can see that scratches arenor noticable, when you are not focusing on them

wil these scratches make more than 1 C CPU temperature difference. If not than it is not worth lapping it.

cozumel

Rolerzzz, you need a totally flat surface to maximize the cooling potential of your heatsink. Yes the scratches will have minor effect on temps but the flatness of the surface when originally supplied by the manufacturer could also be improved on. They will always arrive with imperfections.

As I said before if all you want is your CPU to be cool then stick on HS now and check your temps. They should be ok anyhow - the as5 should fill any scratches and production imperfections. If you have the time then try lapping and see for yourself the difference.

__________________

rolerzzz

Thanks! That is what I wanted to hear. I wil lap it later, after the waranty expires (12 months)

procupine14

just lapped my ac freezer and dropped 8C at load
woowooo

JaccoW

I just lapped my Thermolab Baram and relapped my E8400.
Didn't make any difference, but it already was 5C cooler by lapping it.


Just a wasted afternoon.