Lapping a CPU??

[VortX]

Could someone explain to me what lapping is exactly...

I understand its where you apply sandpaper to a CPU and sand away until you reach the copper base... but what I don't understand is that if it makes a good temp difference (around 5C), why isnt it done as standard, instead of Intel/AMD making a big fat metal base that collects heat?

 

[VortX]

You use lapping paper/wet & dry, which is similar to sand paper, but is a million times finer than sand paper.

Dont use sandpaper!

oooo lol thanks I just got the impression it was very fine sandpaper lol... same thing

 

[VortX]

It would take a lot of time to ensure perfectly flat mirror finish surfaces, therefore increasing production costs that would result in hgher retail prices, its only a tiny group of end users who will lap their cpu anyway, mainly overclockers looking to eek the last few mhz from their system.

True, the main reason I would do it is merely to lower my temps by that extra bit.

Is there any risk in doing it?

 

[VortX]

Some risk, but minor if you're careful with it, don't pour water or oil over it etc.

I'm perplexed as to why they don't come flat as standard. It would take minimal effort to run a milling bit over the surface before attaching it to the processor, and even with it then being plated in nickel one would expect the surface to remain flat.

Anyone know if they're electroplated or dip plated? If the latter, it could well explain why the surfaces are a bit hit and miss. Nickel plating is good because it's inert, copper tends to be attacked by fingerprints and the like

Yeah thats what I was trying to say. Or maybe not so much to make it flat, but even to have less metal on the plate so it isn't so thick? = save money, keeps it cooler?? Or am I missing something?

 

[VortX]

Indeed. Warranty will be void.
If its am oem cpu, the warranty is only one year anyway and may already have run out. Cpus are generally considered indestructible, though in the near future I may have an example of one which is faulty.

This is part of why I've lapped my heatsink but not processor this time around, as I'm not going to return a massive block of metal under warranty. Its better to do both, but temps aren't bothering me much at the moment.


The copper heatspreader is thick because it needs to be very stiff. It takes a lot of pressure during mounting, for a prolonged length of time. It's hardly likely to creep at 60 degrees or so, but if it were very thin it would deform and crush the core soldered behind it. This would be very bad.

Does this mean then that by lapping a CPU you actually decrease its lifespan?