A coppermine 'lapping' tale.


Diamond Member
Nov 12, 1999
i have always lapped my chips/video cards in my often misguided quest for more effetive cooling. with the advent of the itty bitty little cumine core, i was hesitant to touch my 650E with anything, let alone sand paper, and i didn't for the 90 day warranty period(this is a cheap OEM slot 1 from a computer fair - but it overclocks like a mutha). then i read something over at http://www.overclockers.com where a guy had lapped numerous cumines with good results. the seed was planted. the catch in my case was the fact that i had a slot 1 chip which makes for tricky lapping. wasn't gonna let that stop me, and after some tentative experiments i settled on a plan and started lapping. well as you P3 owners know, that core is f.cking small, and despite my patience and care i ended up doming the little b!tch, and reducing its ability to shed heat considerably. now before you start labeling me the idiot that i am, i must say that i attacked the high point in the middle of the slug and eventually got rid of it, and now run at 950mhz/1.78v - 39c/full load 29c/mobo(prime95 for the last 18 hours)with a gorb for cooling, and i am no longer beating myself about the head and shoulders. but i strongly suggest that those harboring this notion(and i know you exist) without access to precision instruments, DON'T DO IT.


Diamond Member
Oct 12, 1999
Lapping means he sanded/ground down into the copper on the core of his cpu. This usually isn't a recommended practice, but its not that hard to do. I did it to my Celery 366@550 and didn't get a single increase!


Oct 9, 1999
I agree, don't do it! Coppermine caps are already as flat as can be when you buy them. I lapped my heatsink though. I have the pure copper HedgeHog heatsink on my 650. I have the combo running at 1021MHz with 1.8V.

Edit: I mean all copper heatsink. It's not pure copper, since it's only industrial grade copper.


Mar 11, 2000
Hmmm... My Celeron II was ultra flat anyway.

Lapping makes sense theoretically but for the vast majority of people it probably will do no good. I always say if you really want to fine, but liquid cooling and lapping are going overboard for a PC.

Plus, my guess is that Arctic Silver without lapping is better than standard thermal paste on a lapped chip.

(By the way, my air-cooled non-lapped Celeron 533A did 960 MHz for several days at 100% load, including OGR, games, 3DMark2000, etc. before locking up once. And only once - ran it for a while longer at 100% load before I reduced it again. Admittedly, I too am going overboard ;) with a copper-endowed Alpha, Arctic Silver, and 1.9 V.)