Lapped my C533A and getting slightly better results!!

[cheche]

This is not for the faint-of-heart!
I was not very sure my cpu would work after this, but it does, and a little better than before.
I am using a BE6-II and the c533a. I could not boot into win98 any higher than 845mhz before the lapping, but now I am in at 923mhz. I can't run Prime yet, but I think it will be possible with a better Heatsink. I'm using an Orb at the moment.

BTW, I lapped the cpu using my Raytech Gemstone cutting Machine, with 50,000 mesh Diamond compond.

So now you Know, it is possible to Lapp a .18 coppermine cpu! But Don't try it just because it is possible, a little to much and it's a Goner!

 

[Yoshi]

Cool.

I don't know why people are so worried about lapping the Coppermine core. The heatslug is sufficiently thick and if you are truely lapping the slug you really should not be removing a whole lot of material.

 

[Eug]

Hmmm... 533A@920 MHz 1.9 V, no lapping, 100% stable - 2 burn-in programs AND graphics running all night all at the same time. I run lower speeds though.

I find it hard to believe that lapping would make such a huge difference. Are you sure it isn't just a better setup - something else you tweaked at the same time?

 

[Toro 45]

Nice job cheche, I was wondering how long it would be before someone tried it.
Toro

 

[Descend492]

Sorry for being an imbecile (I'm an aspiring computer techie, with a long way to go), but what is lapping? thanks

 

[Viper GTS]

"Lapping" is the process of sanding away the excess protective material covering the slug of a CPU, in an attempt to eliminate any imperfections in the surface. Two perfectly flat surfaces will mate perfectly, & result in much better heat transfer. Yes, we're freaks: we sand our CPU's!

How do we do it?

Typically, people will take a sheet of glass (because it's virtually flat, which is the goal) & tape wet/dry sandpaper to it. We'll start with 400 or 600 grit, & sand until the entire surface is scarred. Then we gradually work our way up to 1500 or 2000 grit. At 1500 and above we quit using water, & sand dry. The end result, if it's done right, is a very flat, mirror polished surface.

What do we gain?

Better heat transfer to the heatsink = lower CPU temperatures = higher overclocks, of course.

Isn't it dangerous?

Umm... Yeah. But we're willing to risk it. Plus, if you do it right, it's not nearly as dangerous as it may sound. I've personally lapped 3 CPUs, & have never had any trouble whatsoever. It is kinda freaky washing your CPU, though...hehe...

Viper GTS

 

[StarCropper]

I have a similar set-up as Eug...C2 533A can do 920 at 1.9v; however, I am running at 904 at 1.9 v with Soyo 6ba+iii. I'd like to drop my voltage down to 1.85 v, but when I set the jumpers on my MSI Master slocket to 1.7v, 1.75v, 1.8v, or 1.85v the mobo runs at 1.9v to 2.05v. Thus, I am forced to run at 1.9v for 904. I am not stable at 1.82v 904 MHz. (I get 1.82 by setting slocket to 1.65 and adding the max 10% voltage in mobo bios.)

Is it safe to keep my cpu at 1.9 v for normal everyday use? I haven't seen the cpu temp go above 96 F.

sc

 

[Eug]

Can't you play with the voltage in the BIOS with that board? Are you sure you have everything set correctly? Are you using the latest BIOS?

Dunno about the +III, but the Soyo 6VBA+133 allows to set the voltage on the slotket, then play with the voltage in the BIOS.

So for example you could do 1.7 V plus 10% = 1.87 V, or 1.85 V plus 0% = 1.85 V.

Out of interest's sake, how old is that board, and what revision is it? (It might be hard to tell though, because I think Soyo often has the revision number on the underside of the motherboard.

 

[StarCropper]

My mobo is about 6 months old... There have been a couple bios updates from soyo that I haven't used. I had another soyo 6ba +iii that wouldn't boot because of eprom corruption after i flashed the bios with one of Soyo's updates. Ever since that, I have been reluctant to trust soyo's bios updates.

sc