Lapping and dehydration

[Asha_abx]

Wowiee
I just lapped my cel 600 and that is very effective.
I sweted like an ox during the process itself, I was afraid my swet would distroy my cpu.
But it was deffinitely worth the trouble. It lowered my cputemp at least 2 degrees celcius, I think even a little more being idle (never paid much attention).

GREAT.

Just sharing my happiness

grtz Asha

[Sir Skully]

Asha, thats GREAT! Glad you got it done without wrecking the CPU. I know what you mean, as I've lapped a few CPUs.

[rdmpe]

Do you do the lap to make the covering on the top thinner, or just to make it flatter?

[Asha_abx]

Well with older chips (not with pIII) I read that some people actually went down to a copper surfase. But I did it mainly to get it flat, off course every bit off is good but I was scared ****less. Afraid that once I stopped and turned it over I would see the actual chip and then off cource it would be too late(p3s dont have a copper housing as far as I know so....). So I stopped as soon as possible, when it was flat and smooth and very very shiny )

grtz Asha

[Heavenly_abx]

Hi
You should think that the PIII Coppermines would have a copper housing like it's older brothers if you hear the name Coppermine !
Well it doesn't have a copper housing so lapping it is only done if you have a chip that has a dip in it , otherwise i think it is a tricky job because the core of the cpu is very close to it's surface and a couple of strokes extra with sanding papier shows you all 24 million switches a PIII has!
Good luck !
ps I could not resist the urge at some times and lapped a few , not one went bad but it cost me a year of my lifetime because the nerves it took !!

[rdmpe]

Gimme some details. What sandpaper grit(s) and with water? And did you tape the sandpaper to a glass table or something?

[Heavenly_abx]

Hi , you start with raking a black waterproof marker pencil (men it gets to me if i don't now the right word in english) and make the cpu surface black , then take a old antistatic back and cut a hole in it the size of your cpu surface and tape it real good so no water or shavings from the sanding can get on your chip.now youre setup to do the sanding , attach some grit 200 wet sanding paper to a completely FLAT surface like a piece of glass and hold the cpu die down on it and make sure you wont wiggle while sandin. Make strokes on the wet papier like making a 8 figure and check now and then if all the black marking is shaved of , when it is then you know you have a nice flat surface . Change to 600 grit paper and agian hold it really flat to the paper , dont put to much pressure to it , sand it down until the very deep scratches are gone and it looks to be pretty smooth. For the finishing touch you have to "polish"it with grid 1200 sanding papier till it is shiny like a mirror and smooth as a baby's but !! You now have lapped your cpu ! Most cpu die is alreaddy flat but the blue stuff on it is ment to be a heat conducting seal , but you get more heat conductive when it's lapped of and then use some Artic Silver thermal grease.Again , it is very important not to "wiggle" the chip when sanding. Some people say that for getting a perfect match between cpu and heatsink you should use the heatsink as a flat surface, i havent seen one heatsink wich is as flat as a mirror. For the best result you have to lap the heatsink in the same way as you did your cpu. Wel i think i covered it all ,if you need more info post a reply.
Good luck!

[Asha_abx]

Hmm well I don't know about that water part. So I did it a little different from your way Heavenly.
I used two kinds of grind paper 800 and 1200.
I taped them to my table, which has some kind of plastic topping, so no wood nerves. I cleaned the cpu really wel with some tissue and then placed it upside down on the 800 paper. Put one finger in the middle of the chip and tried to make even eight figures. After about 30 8s I changed paper and then ended up doing a lot of 8 before it was nice and shiny (next time I ll do some more on the rougher paper).
Then I cleaned the cpu with some thermal paste, it removed the fine shaving dust really well.
And then reapplied the cpu. I havent done the heatsink. I might yet cause it looked kind of rought from where the edges of the eneven cpu "cut" into it.

grtz Asha

[Heavenly_abx]

hi Asha , sure you can do it dry also , But as explained to me when i did the first one a couple of years ago it was al done with waterproof sanding paper. If you see how it is done at this time it is totaly different again, now the don,t use sanding papier but diamond powder, they use grid 200/600 and finish with 1200. It's done on a piece of glas and a little bit of diamond powder and a drop of water. I have done one a couple months or so and it works also great but the advantage was only that you don't have to tape sanding papier down to a mirror. I have to disagree to do it on a smooth surface like you describe because you can never be 100% sure that it is flat , glass thoug is always flat and the surface of glass is smoother then anything i can think of!!
I think you have to do both the cpu as the heatsink to get the best result , it's a waste of time and effort if you dont do the heatsink aswell when youre doing your cpu.
Good luck !
ps , with the socket 370 i think it's better to do both at the same time because the socket sludge seem to be a weak point. you have to remove your heatsink only once if doing them both.

[Asha_abx]

Thanks Heavenly,

Yep a mirror now why didnt I think of that
I have an gorb so I ll try to see if I can do that one tomorrow. See if all the metal parts stikking out can come off.

asha

[rdmpe]

I am going to try this lapping, as my temps of 19C over ambient are too high I think.

Also, I replaced the greenie on my mobo with a TennMax fan (www.tennmax.com) that I had around. The AGP chip is SO CONCAVE it is pathetic. It only touches the hs at the corners! So I had to put a gob of arctic silver to seal up the cavern between the hsf and chip. And the greenie is flat, so they didnt' touch originally. Probably a waste to put the greenie on there as it just blocked airflow without touching the chip!

Also put a hs on the clock chip.

[Heavenly_abx]

Hi Randyminer , 19 degrees celsius above ambient is indeed to high , what kind of heatsink are you using , and why the high vcore of 2.0 ??

[Asha_abx]

Why is a cpu temp of 45 "to" high? If you reach that temp under load there should absolutely be no problem.
Is there a general "rule of thump" I am not aware of that says something about the difference between core and ambient? I thought that If you have a low ambient you can probably just clock a little higher.

I lapped my Gorb but that didn't do anything
Well if I lapped the orb first the lapping of the cpu probably wouldn't have made a difference

grtz Asha

[Heavenly_abx]

hi Asha , In the case of randyminer a temp of 19 degrees celsius above ambient is 40+ on idle , if he's at full load the he will proberly go into the 50c , when overclocking your system temps are a factor wich can stop you from o/c higher then you would if the temps where lower . The temp showing in the sensors are actually not the temp that is inside the core , they are measured at the core but not really in the actuall traces in the core , it,s a real technical proces wich i don,t now exactly but it has to do with acceleration and current that takes a little bit of the core and builds up untill it reaches another switch and then shorts out. This is the best i can explain it being non english. Anyway the lower the temp stay's the more stable is your system , this is ofcourse not the case if you can stay at low 40's
at full load. But if you push your chip really high then the chance at succes is also depending of temp. My other system, a PIII450 would go to 129 mhz and if i try'd any further it locked up , after adding a pelt it runs at 133mhz and higher if i want but loose stability and get corrupted data , this shows that the temp is one factor that can get you at higher speeds. If you want to now exactly then you should go to http://www.overclockers.com they have a couple of articles about temperature and O/C. It's a real difficult subject. Have fun !!

[Asha_abx]

Thanks Heavenly,

I know most of that although not the real technical part.
Anyway like I said I didn't know whether he meant at Idle or at full load.

grtz Asha

ps wow your a premium member now! congrats