Tue Jun 11, 2013 10:23 am
The only thermal compound I've ever found to make an actual measurable difference is Coollaboratory Liquid Pro, which I've had knock a full 10 degrees off, and even more on de-lidded CPUs.
I haven't used it in years though, as that stuff is naaasty if you ever have the slightest inclination to remove the heatsink again at some point. It's practically impossible to remove completely once applied.
As far as conventional compounds go, everyone has a favourite, and it's usually the one they've tried, and did the job perfectly well.
The two things that actually make a real difference are:
- learning to apply the paste effectively - you need to apply the thinnest possible layer that still makes even contact across the whole chip/heatspreader. A thicker layer will raise temperatures considerably, as the thermal compound will always have worse thermal conductivity than the two pieces of metal you're putting it between.
- de-lidding the CPU, at least ivy/haswell CPUs, where they've stopped using solder as a thermal interface. One weak link is way better than two weak links - the "heatspreader" on modern CPUs is there for one reason and one reason only - to protect the silicon underneath from reckless heatsink installation, and thus from needless warranty claims. It doesn't serve to "spread" the "heat" any more effectively than a dirty-great heatsink mounted directly to the chip.
If you're really obsessed with cooling efficiency, these two points will make way more difference than which brand of compound you use, and if you're not obsessed, then none of it really matters, as all but the most powerful server processors are easy to cool to a perfectly adequate level, with minimal noise, just by picking a decent cooler.