Extreme lapping

[stormont]

As mentioned in one of my earlier posts, I was lapping the heat spreader on my 1.6A and went a little too deep. I exposed what looked like copper underneath the nickel. I went ahead and sanded it down to a complete layer and sure enough, copper it was. Used Artic Silver 3 between it and the lapped stock intel P4 cooler (the block, not the Sunflower clone) and here's what I get:

147 x 16 = 2.35 MHz @ default voltage
Ambient Temp: 19 C
System Temp: 28 C
CPU Temp: 40 C (at full load after 1 hr)

I tried installing the SunFlower I have and the temps were higher. I tried installing it multiple times just to make sure it got mounted correctly, and the temps were alwasy higher. I'll see how high I can push this setup and post in the poll. Here's a pic:

Lapped CPU

 

[MrThompson]

Did you use any polish or cleaners? Polish and some cleaners will fill the microscopic surface imperfections where the thermal grease should be.

With a highy lapped surface, the amount of thermal grease necessary is almost nil. Arctic Silver 3 is designed so the excess grease will flow out of the thermal junction. Apply a thin, translucent layer and give it a few days to settle.

 

[stormont]

I only used 800 grit and 1000 grit paper; no polish. I'll wait a couple of days and maybe try some.

 

[Blain]

Now that the less conductive nickle layer is out of the way you should be able to ROCK ON

 

[bacillus]

for best results just remove the heatspreader completely!

 

[stormont]

I've heard arguments both ways regarding removing the heatspreader. The entier spreader is nickel coated, right? So as it stands now, there is still nickel touching the core, but copper exposed to the heatsink.

I know people are different, but what is a reasonable temperature threshold? The max temp for a Northwood 1.6A is 66 degrees C. I'm just trying to decide how high I want to push it.