Lapped my XP-90... 4C temp drops = 24C on AIR

[kevinbo03]

First off, My motivation and my opinions. I did this because I was bored, And thought I could show off my technique for lapping. I also wanted to get my CPU to 25C idle, Just for the heck of it.

About Polishing with Noxon\Brasso:

Yes- Having any foreign material sitting on your contact surface will hurt thermal performance. However, Metal Polishes cut very finely into metal, And result in a Much smoother finish. Also, A few minutes of buffing with Isopropyl and Microfiber will remove any and all remnants of Polish, Wax, Etc.

The Procedure:

Wet Sand with Lubricant + %99 Isopropyl on grits:
-400
-600
-800
-1000
-1500
-2000

THEN

Noxon 7 Metal polish + 2000 Grit

THEN

Noxon 7 Metal Polish + 90k Microfiber

THEN

No7 Chrome Polish + 90k Microfiber

THEN

TurtleWax compound + 90k Microfiber

THEN

Clean and buff with %99 Isopropyl + 120k Microfiber



I Also added some AS5 Epoxy to the area where the Heatpipes connect to the base. The end of the heatpipes left a small gap around them, SO I just filled in the extra space with the AS5 Epoxy. This can be seen in the 5th attachment.


Performance:

All of the listed temperatures are averages of 2 minutes idle after 30 minutes Idle, In My room (Which was kept at 62F for testing purposes). The SYS temps is higher for two reasons. For one, The Temperature probe on my motherboard is placed in a poor area. It is right next to 3 heat producing chips, And receives no airflow.

Temps Before:
CPU - 28
SYS - 28
PWM - 38

Temps After:
CPU - 24
SYS - 28
PWM - 38



Any comments and questions are welcome.