PIII CPU Lapping

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UPDATE 2/22/00: Never accuse Aaron Lephart of letting grass grow under his feet! Aaron sent in his PIII Lapping results:

“After reading a short article on your website today I decided to lap my PIII650 which was currently stuck at 793 MHz with 122 FSB on my ABIT BE6 II. After lapping it I was amazed at the 15C drop Sandra99 and the PC Health Status in the bios reported. From there I started upping the FSB in 1MHz settings.

I got all the way to 128 FSB before upping the voltage from 1.7v to 1.8v where I got up to 132 MHz FSB. That’s 858 MHz stable I am getting out of this chip which is awesome. I am using Corsair PC133RAM and a KryoTech Renegade cooling system with a VooDoo3 3000 AGP card and a SBLive sound card. Enclosed is a Sandra99 benchmark screenshot along with before and after PIII650 lapping pix. Thanks for all the help your website has been.

PIII Before and After

Not a 2 chip PIII – I’ve inserted the “After” pix – the black is protective tape while sanding.

PIII Results

Email Aaron

UPDATE 2/21/00: Email from Nate: “Read the review of the PIII Lapping. I thought I’d let you know that the PIII-core is a flip-chip core, and by lapping, you are actually lapping the core
of the CPU. Unlike PII’s and Celerons, there is no copper slug in the PIII package. In reality, you are sanding the silicon core itself.

The blue coating is a thermally conductive sealant. The whole flip-chip concept has only recently come to light due to Coppermines, but it is important to note that nearly all 450MHz+ Pentium III’s are
flipped as well. I sanded my PIII-600, and it worked fine after sanding, but it is still very dangerous. If you are lapping, do NOT sand too deeply… you will sand off the processor core.”

Email Nate

Original Tip:

Hi buds – I see you ain’t got no details on lapping of P3’s? Bah to that, so I gone and done it myself. Attached are 4 pics:

CPU before and after and temp monitor before and after; didn’t go mad on the lapping as it was my first effort and not knowing how the CPUs are made I was a bit worried about trying for this mirror copper finish every one blabs on about (does the p3 have a copper slug thingy?).

CPU Before Lapping

Temp Before Lapping

Anyways just lapped down to a nice finish and achieved massive results – a constant drop of 10C (which is nice), roughly about 20% better than non-lapped. It’s a standard p3-450 (@600) with a Global Win heatsink.

I would definitely recommend this to all people who like to dice with their PCs.

CPU After Lapping

Temp After Lapping

Email Colin


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