[Review] Indigo Xtreme vs. AS5, MX-2, IC Diamond, Shin-Etsu X23-7783D

[SergeantNathan]

I was assembling a system for a client today, so I took the opportunity to play with my ICD-thinning idea. The CPU was an AthlonX4-640, lightly OC'd to 3.3GHz. I used the stock 1055T heatsink that I had lying around as it's better than the stock 640 heatsink. I plugged the fan in with a molex-to-3-pin adapter to ensure the fan stayed constantly at 100%. First was a quicky application of NT-H1 (since it supposedly has minimal cure time, and I had little time to do this little test). Stressing it then letting it cure overnight, I took the max load temps. When I dismounted the heatsink, I found the bondline to be a bit thick, even though it spread enough to cover the core sufficiently.

I spent a little more time applying the ICD. I used around the same amount of material as I did with the NT-H1 (about the size of a grain of rice), but dipped a tiny flathead in the 99% isopropanol and mixed in the droplet with the ICD. It was a bit thinner than the NT-H1 at that point... I didn't want it much thinner, as the finish on the heatsink was very rough. I quickly mounted the heatsink before the alcohol burned off, applying extra pressure to ensure a good mating. The results were impressive. A 6 degrees Celsius drop (lol... 6 degrees of separation...). I doubt that was merely due to the better performance of ICD alone... the application probably made most of that difference. And this was with hardly any curing time. Dismounting the heatsink showed a thinner bondline and a healther spread than I had with the quicky application of NT-H1.

To prep the system for deployment, I went back to the stock heatsink. After cleaning off the stock TIM, I found the base to be much better finished than the 1055T heatsink. So, this time, I mixed in two droplets of alcohol to a drop of ICD (it took a good 15 seconds or so of mixing to get an even consistency) and quickly mounted the heatsink, as I could see the alcohol quickly burning off. I applied some extra pressure and some torquing back and forth to really mate the surfaces well before locking it down. I was impressed that with this optimum application of ICD, this significantly inferior heatsink performed only 3 degrees worse than the 1055T heatsink with a quicky application of NT-H1 (plus the 640 heatsink's fan was a tad bit quieter).

This wasn't meant as a comprehensive test, just a dabble in curiosity. One hypothesis I have about a downside of this method is the drying out of the paste. This in-and-of itself may not be bad, but if the heatsink shifts at all, there is no liquid carrier left to adjust to the shift, and the mating would probably be seriously compromised. I guess a quick way to test this theory is to torque a heatsink with a Indigo Extreme application enough to "break the seal" and see how much performance suffers. This issue is why you're told never to re-use paste, and why I always use "wetter" pastes on videocard heatsinks (since they tend to be much easier to shift around accidently). Anyone care to test this out?



***Ambient was kept darn well near spot-on 23 degrees Celsius throughout. I only posted relative temps since the CPU temp sensor wasn't calibrated worth crap, listing idle temps well below ambient***


***I should also note something I did with each ICD application that may or may not have improved its results. I put a little dot of ICD on the heatsink, and then poured a dollop of isopropanol on it and then used a lint-free cosmetic pad and lightly polished the heatsink, letting a super thin layer of TIM to remain rather than completely cleaning it off. I then used the same, still-moist-and-traced-with-ICD pad to do the same on the heatspreader***