Lapping risks

Crashgate3

Crashgate3

Crashgate3

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How easy is it to break a chip when lapping it? The actual process itself looks fairly straightforward, as long as you take your time and make sure you buy enough grades of paper and a suitable flat surface.

However, part of me really doesn't like the sound of rubbing something course against several hundred pounds of delecate electronics. What's the danger of something like static or even just well-meaning heavy-handedness breaking something?
 
Crashgate3 said:
How easy is it to break a chip when lapping it?
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Depends whether or not your talking about a chip that has pins or not however as its 2008 I assume you mean a pinless cpu.

I can't see an easy way you can break or damage a pinless CPU from lapping, all you are doing is sanding a very slim layer from the Integrated Heat Spreader (IHS) which is just a protective metal shell above the actual processor.

If you were to sand away like a crazy person for an hour or two then you may actually sand through the IHS and start eating into the core?

The lapping process is pretty gentle, the chip doesn't get knocked or banged about so its not a problem. I think you would have to give one of these chips a really big whack to damage something internally?

Practice your lapping skills on someone less precious then when you are confident give the heatsink or CPU a go, its quite easy once you've practiced :)
 
Unless the chip was somehow not watertight. Copper particles get in and possibly short it out. Dunno if the manufacturing process eliminates this. Mine looked fine when i did it.
 
Hang on, pinless cpus? I have an AMD 4400X2 and it has pins, I've thought about lapping this but always wondered how to hold it without risking bending pins. Are you saying that new cpus, i.e. penryns, q6600 etc, don't have any pins?
 
Yeah, the pins are on the board and the actual 'socket' is on the botoom of the chip (although obviously the mounting clamp is still on the board).
 
What are the actual performance benefits of lapping the CPU? Does anybody have before and after comparisons?
Seems like the risk of contamination/damage and time spent is not worth the benefit to me.

Does any manufacturer supply ultra flat CPUs out of the box?
 
OneSexyNerd said:
Does any manufacturer supply ultra flat CPUs out of the box?
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I've never had one :p

Lapping pros - Will improve contact between IHS and Heatsink = Better temps.

Lapping cons - Will void warranty

You could remove the IHS completely - This will also void warranty.

Mark
 
I have never killed an AMD chip by lapping or removing the IHS. Both are really quite simple to do but obviously void the warranty.

From experience, removing the IHS and lapping the base of whatever bolt down CPU cooler you are using reduces temps the most. My current chip is naked and I have lapped my TRUE 120.
 
OneSexyNerd said:
What are the actual performance benefits of lapping the CPU?
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Well you would normally lap your heatsink first then maybe you would consider lapping the processor. Some CPU's have a fairly uneven IHS so it doesn't make as good as contact as it could if it was flat.

The flatter the Heatsink and chip are the better the contact and therefor the cooling. This doesn't really effect people who are running their chips at stock but its becomes an advantage to those who intend to overclock their chips to the max.

OneSexyNerd said:
Does anybody have before and after comparisons?
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There is quite a few threads on this already posted if you search you should get the info you seek. Here is a small screenie of my temps from an E6300 chip before and after lapping, the CPU didn't really need doing and most of the gains came from levelling off the base of my thermalright Ultra120 which was pretty badly concaved. . .

unlappedvslappedvz4.jpg


Knocked 15°C off my load temps which I would say was worth the effort. Its nearly always worth lapping a heatsink but I can understand why some people would be hesitant to attack their cpus with sandpaper and I wouldn't recommend this till after lapping the heatsink first.
 
only probs ive read about when lapping is 1,if you lap in a circular motion its very easy to take to much of the corners and 2,if you have to much water on the wet and dry paper,you dont want it to build up into a puddle.o and obviosly take the usuall static precautions:)
 
Big.Wayne said:
Knocked 15°C off my load temps which I would say was worth the effort. Its nearly always worth lapping a heatsink but I can understand why some people would be hesitant to attack their cpus with sandpaper and I wouldn't recommend this till after lapping the heatsink first.
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15C is not to be sniffed at! Thanks for posting. I guess the potential gains depend on how flat the components are to start with.
 
I've been hanging back from lapping through laziness generally. But whenever I see reports on such temp drops I'm encouraged to again.

My stock E6600 idles at about 46C on 1 core and 50C on the other.
At 2.7Ghz that jumps to about 60C. On my ACF7 Pro. Is this cooler know for concave-ness?

I always thought you should start with lapping the CPU but maybe I and the OP should start with the heatsink
 
I just got a E2180 and a AC7 pro and the first thing I did was lap the AC7. I have an older average case that I have tried to make as " airflow friendly" as possible but I get pretty good temps after lapping. 35-36 idle and 62 while running prime or orthos overclocked at 3Ghz. in the games I play it stays in the low 50's. Once you start the lapping process (which this was my first time) you really begin to notice just how uneven the heat sink surface is. I was going to do my cpu but im pretty comfortable with my temps but if I decide to go higher ill lap the cpu for sure.

All in all it was pretty painless. just get one of those little combo sand paper packs you can find at auto shops or hardware stores and a spare hour or so and your set. I do not know if all AC7's are like mine(the unevenness) but for the fairly painless and short time it takes to lap the sink I really think its worth it. Just make sure the surface your going to lap on is a flat one. I had a little thick glass plate I used.
 
A little tip if youre struggling to find a bit of glass to lap on, check your fridge. Most fridges will have a glass shelf above the vegetable thing at the bottom. Was just the job when I lapped my sink.
 
hybrid: said:
Do you have to remove the IHS before lapping then?
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No, you would either lap the IHS with it still attached to the processor *or* you would attempt to remove the IHS completely.

These are two different options, lapping is pretty much risk free but removing the IHS completely has a much greater chance of damaging the CPU.
 
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