Heatsink lapping.

> > I don't buy the whole Arctic Silver thing. It's just heat sink
> compound,
> > people..
>
> You ought to do some experiments with it. Arctic Silver does make a
> difference. :)

Although I use Arctic Silver myself and will continue to do so because it does do a good job of spreading very thinly, not drying out, and is very easy to apply, I don't think it makes much of a difference to the thermal transfer. I think that lapping as described in the original post is far more important. If you want a very illuminating read on tests of various compounds (and various spoof items), look at this review. Its an extremely entertaining read, as is most of the stuff on this site, and here is a quick summary of results. First of all a direct quote of the experimental method:-

By monitoring the voltage across the heater's 4.7 ohm power resistor I can tell how much heat it's outputting. And with a dual-input thermometer that lets me see the ambient air temperature, the temperature of the probe inside the heater, and the difference between the two (delta-T), I can tell how well the cooler's managing to get rid of the heater's output, without the result being polluted by changes in the ambient temperature.

Divide the delta-T by the heater wattage, and you get a number in degrees Celsius per watt (°C/W). The lower the number, the better.

I've listed the actual numbers that are reported in the article:-

01. No thermal compound at all. -----------------------------> 0.66°C/W
02. Zinc Oxide thermal compound. --------------------------> 0.50°C/W
03. Arctic Silver 3 thick layer. ---------------------------------> 0.50°C/W
04. Arctic Silver 3 thin layer. ----------------------------------> 0.48°C/W
05. Arctic Alumina thin layer ----------------------------------> 0.50°C/W
06. Cooler Master's gold-tube, grey-grease PTK-001. ---> 0.50°C/W
07. Cooler Master HTK-001 (white grease) ----------------> 0.50°C/W
08. Nanotherm thermal compound (2 days bed-in) ------> 0.50°C/W
09. Toothpaste (yes, read the full article). -----------------> 0.47°C/W
10. Vegemite (an Australian thing - yeast extract) -------> 0.48°C/W
11. Straight water (yes, read the full article) --------------> 0.41°C/W

It's really wierd that both toothpaste and Vegemite are as good as or better than AS3, for the short period of the test anyway.

There's a lot of interesting and useful stuff on this guy's site.