Now let’s see how the thermal interfaces perform on the open GPU die:
I had no doubts about the efficiency of the liquid-metal Nanoxia TF-1000 even though its advantage amounts to only 1°C of peak GPU temperature in comparison with the other products. The leader is followed by as many as 12 thermal interfaces from the Thermaltake TG-1 to the Nanoxia Heat Buster which differ by about 3°C in terms of peak GPU temperature. The renowned brands are all in this group. We can only note that the Tuniq TX-4 and ARCTIC MX-3 do not have much advantage over the TX-3 and MX-2, respectively. The Glacial Stars IceTherm II is the cheapest thermal grease in the leading group.
Next goes a group of eight products, differing by less than 1°C amongst themselves and by about 2°C from the leaders. It is rather surprising to see the Arctic Silver 5, which used to be a recognized leader, in this group as it is inferior even to its entry-level cousin Arctic Matrix. Perhaps its low results are due to the lack of time for “breaking in”.
The group of losers includes liquid greases like the Xigmatek PTI-G3606, Deepcool Z9 and Thermaltake TG-2. By the way, Thermaltake's two products take the top and last places in the standings if we don't count in the liquid metal Nanoxia and the Indigo Xtreme. The difference between the same-brand products amounts to 12°C!
Next I checked out the efficiency of three thermal greases with my CPU. First I took the Thermaltake TG-1 as the best performer in the previous test:
The Scythe Thermal Elixer represented a medium-efficiency product.
And the Thermaltake TG-2 had the worst result in the previous test:
So, here is how these three performed with my CPU:
So, the standings have not changed but the gaps between the products have diminished. The leader Thermaltake TG-1 is superior to the Scythe Thermal Elixer not by 3°C as on the graphics processor but by about 2°C only. The worst thermal grease of this test session, Thermaltake TG-2, is now only 5°C worse than the leader although the difference was as large as 12°C on the graphics processor. I guess this must be due to the convex heat-spreader of my six-core CPU. The ideally flat die of the graphics processor and the graphics cooler with a perfectly flat base provided much better test conditions.
I also tested these three thermal greases with a Zalman CNPS10X Performa cooler (with two Thermalright TR-FDB fans at 2040 RPM set for exhaust and intake) and received the same results.