Both of the compounds

We should all know that some kind of thermal compound between the CPU and heatsink in order to aid heat transfer and keep your precious CPU cool. A cooler CPU could lead to the ability to overclock the CPU that little bit more which is always good. ;)

There are a number of different heat transfer compounds about like the pink chewing gum type pad (Ed: it's called a TIM !!) that is found on the bottom of a lot of heatsinks. This stuff is pretty useless if you want to get any decent speed out of your CPU. One of the other options that is being reviewed today is the specialist thermal pastes, Arctic Silver 2 and Arctic Alumina.

Arctic Silver 2 and Arctic Alumina are both from the same company but have different properties. Arctic Alumina is the newest creation from the makers.

Artic Silver 2

Both of the compounds

• Made with 99.8% pure micronized silver.
• 78% to 82% silver content by weight.
• Extended temperature limits: - 40°C to >160°C
• Minimal viscosity change from 0C to 150C
• Thermal conductivity: 8.4 W/m°K to 8.8 W/m°K (Hot Wire Method Per MIL-C-47113)
• Thermal Resistance: 0.0028°C-in²/Watt (0.001 inch layer)
• 2 to 7 degrees centigrade lower CPU core temperatures than other thermal compounds.
• Negligible electrical conductivity.
• Arctic Silver II was formulated to conduct heat, not electricity. It is only electrically conductive in a thin layer under extreme compression.
  (While much safer than electrically conductive silver and copper greases, Arctic Silver II should be kept away from electrical traces, pins, and leads. The compound is slightly capacitive and could potentially cause problems if it bridged two close-proximity electrical paths.)

Arctic Alumina Compound uses a layered composite of aluminum oxide and boron nitride to provide near Arctic Silver II level performance.

Arctic Alumina Compound is a pure electrical insulator, neither electrically conductive nor capacitive.

Arctic Alumina Compound does not contain any silicone. The suspension fluid is a proprietary combination of advanced polysynthetic oils.

Arctic Alumina is the first thermal compound engineered for controlled triple phase viscosity. The complex polysynthetic oils work together to provide three distinctive functional phases. As it comes from the tube, Arctic Alumina's consistency is optimized for application in a thin, even layer. During the CPU's initial use, the Arctic Alumina compound thins out slightly to enhance the filling of the microscopic valleys and insure the best physical contact between the heatsink and CPU core. Then the compound slowly thickens over the next 20 to 100 hours of use to its final consistency designed for long-term stability.

Arctic Alumina Compound cleans off easily from CPUs and heatsinks.

Testing

In order to make it as fair as possible the only thing that was changed during testing was the thermal compound. Between each test the CPU was cleaned thoroughly of with Isopropyl Alcohol, to remove all traces of the previous thermal compound, before applying a different compound.

To test the CPU at full load the computer was left with United Devices Cancer Research running for 10mins straight after startup had finished. Then all programs where shutdown and was left for 15mins to cool-down for the idle temperature. During the testing the motherboard temperature was monitored but never changed during testing

For Application information please go to Artic Silver.

Results

	Artic Silver 2	Artic Alumina
CPU Load	39	39
CPU Idle	28	28
Mobo	22	22

Conclusion

The results for the two are the same, however there are some advantages of using Arctic Alumina over Arctic Silver 2, like it is not electrically conductive or capacitive whereas AS2 is. So now with Arctic Alumina there is absolutely no chance of shorting out the CPU, while an extremely slim chance with AS2. Also the price for Artic Alumina is expected to cost less than Artic Silver 2.

So in conclusion both are very good products but if the opportunity is there Arctic Alumina is probably the better of the two due to its improved properties.