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.