A major part of every overclockers' toolkit should be a nice assortment of thermal pastes. For most of us, those little packs that come with better heatsinks make up our collection of pastes. However once you've had a taste of what a really good thermal paste can do, its hard to go back to those little packs. There are the silver pastes sold by special overclocking sites, and there are the generic white silicon compounds. There are also quite a few non-silicon based thermal compounds, three of which we'll be looking at in this review.
Generally speaking, thermal compounds are horrible at transferring heat energy. Where copper can transfer upwards of 398 W/m*K, the average thermal compound hangs in at around 0.70-1.4 W/m*K. So why would anyone want to put such horribly unconductive goo on their processor? Two reasons really. Thermal compound fills in the small voids that exist between a processor core, and the base of a heatsink. This improves the path by which heat energy travels. Improve? Well the alternative is to have air fill those voids. Air is much worse at transferring thermal energy than even the poorest thermal compound out there. The tradeoff is an improvement - so long as the compound is applied properly.
This has been drilled into everyone's head a million times, but I find myself
even putting too much thermal goo on sometimes. Heck, I once saw our man 'west',
hands covered in thermal compound, and heatsink almost totally white! So how
much compound should you apply, and how should you apply it? The best way I have
found to apply thermal goo is to put a very small dab on the core, and spread it
around with a piece of rubber or plastic to get a layer of uniform thickness.
The finger method may be easy, but rarely ever gives you good consistent
coverage. In the days when processor dies didn't have their silicon exposed it
was also a good idea to rotate the heatsink atop of the processor to remove any
excess compound. Now a days I don't recommend that at all. It scratches the
silicon too much.
With all that out of the way, we're going to be comparing some new non-silicon
based heatsink compounds. While they won't quite be up there with the
silver compounds I suspect, they all perform markedly better than any standard
silicon based thermal compound I've seen so far. The best aspect of these
compounds is that they don't dry out like the cheap thermal compound usually
does. There is nothing worse then taking off a heatsink and chipping away
at dried out thermal compound. So far these compounds have proved to be very
stable with in terms of evaporation and hardening with time.