Arctic Silver 5
The Arctic Silver 5 is a time-tested overclocker-friendly thermal interface. It is widely regarded as an etalon among thermal greases and new products are often compared to it. I've got it in a new large 12-gram syringe for $23.
It is available in a smaller and cheaper portion: 3.5 grams for $8. The Arctic Silver 5 features a very high thermal conductivity of 8.7 W/(K·m), which is the second highest value in this review (excepting the liquid metal). It is made of zinc oxide, aluminum oxide and boron nitride particles. Its color is silvery gray and it is viscous but not hard. A strong adhesion is a special feature of the Arctic Silver 5. It does not contain silicone, a unique mix of synthetic oils serving as the binding agent. The Arctic Silver 5 does not conduct electricity, does not leak and does not dry out. It achieves its peak performance in 50 to 200 hours and keeps it for a long period of time (the exact period is not specified, though).
This thermal grease is easy to apply and smudge on a component surface to get a thin and uniform layer of it.
There are also no problems cleaning the component from this grease afterwards. By the way, the Arctic Silver website offers detailed instructions on applying the thermal grease on most CPU types.
Cool Age CA-CT3 Nano
The Cool Age CA-CT3 Nano comes in a small 2-gram syringe with no packaging.
Manufactured from nano-particles, the Cool Age CA-CT3 is specified to have a thermal conductivity of 5 W/(K·m) and a thermal resistance of less than 1.194°C-cm2/W. No other parameters are declared.
This thermal grease is thick but soft. It is very sticky and its color is light gray.
The Cool Age CA-CT3 Nano is a dielectric. It does not leak and does not dry out for a long period of time. Thanks to its plasticity and, perhaps, to those nano-particles, I easily got it spread out in a very thin and uniform layer. Its imprint on the GPU and heatsink surfaces was just exemplary:
This thermal grease was also easy to remove.