Pro-Thermal 81

We couldn’t find any information about new Pro-Thermal 81 thermal compound. There is nothing about it online, and the sticker on a small syringe says that it is made in Romania and weighs 1.5g:

This thermal compound is of light-gray color and relatively liquid consistency that is why it can be easily applied and removed:

We do not know the exact price of Pro-Thermal 81 thermal compound, but we believe it is around $1~$2.

IC Diamond 7 Carat

This product from Innovation Cooling Company comes in a simple plastic bag that contains a 1.5g syringe. The name of this thermal interface – “Diamond 7 Carat” – suggests that there is some connection to diamonds. True, according to the manufacturer, it contains ground synthetic diamonds with up 40 µm particle size.

The manufacturer claims that the thermal conductivity of its product is 4.5 W/(m·K). However, synthetic diamonds are known to have 2000-2500 W/(m·K) thermal conductivity, which is 230 times higher than that of Arctic Silver 5, for instance. Nevertheless, you should keep in mind that we are talking not about pure synthetic diamonds, but about diamond dust with some additional filler that most likely has considerably lower heat conductivity. Diamond 7 Carat doesn’t leak, doesn’t conduct electricity and doesn’t change its features with the time. It requires only a couple hours run-in time to reach maximum efficiency.

This thermal compound is very thick that is why it why it contains special solvent that liquefies the compound in the first few minutes after application. Once applied, you should wait for 10 minutes before installing the cooler, so that the solvent could evaporate and the synthetic diamonds could crystallize. After that the thermal compound layer becomes glossy-gray. When we removed the cooler from the CPU, we saw that Diamond 7 Carat became very hard, but spread evenly over both surfaces:

This is a pretty interesting compound, I should say. However, only practical tests will show how efficient it actually is. Here I would only like to add that it is priced at $5 per syringe, which is quite acceptable compared with the other solutions discussed in our roundup.