The most popular type of thermal compound has silver suspended in silicone grease. Research has been done by overclockers.com demonstrating a far superior type of thermal compound using diamond. Silver has a respectable thermal conductivity at: 429W/m K. Diamond on the other hand has a thermal conductivity of 900-2320 W/m K. So worst case scenario we double performance, and best case is roughly a 5x multiplier.
Another nice advantage with diamond is that it is not electrically conductive. Silver based compounds will conduct electricity which makes a sloppy application of the compound a risk for shorting out your expensive hardware.
It appears that several people have come up with this idea independently, but we didn’t want to make that fact stop us from sharing our two cents on the matter as well. There are mumbling's about commercially available compounds being in the works but we thought, “Why wait when we can have our candy now?” We are going to show you how to make your own diamond compound, and provide you with some of our own results for the improvements it provides in actual cooling performance. We will be comparing Arctic Silver to our home brewed batch of diamond compound. Pending some more testing and refinement we will be giving away a few "experimental samples" in a week or 2.
25 Carats (5 grams) of 60,000 mesh diamond powder available for roughly $30 on eBay or as raw material, sometimes used in buffing compounds.
It’s worth mentioning that the purity of the diamond powder is an important factor. While most industrial diamonds are pure, some less than honest peeps will mix in other materials. Check on the purity with your vendor.
Silicon grease compound containing: Polydimethylsiloxane and Polytetraflouroethylene. This is available at some hobby shops or your local chem shop. Make sure that the compound you get does not have a thermal conducting component like zinc oxide as this would provide an insulating value compared to our diamond.
Tools that we used: ( I.E. you may want to use as well )
One note on power tools: use them at your own risk. Be sure to read and understand any and all documentation on the tools you use. No amount of documentation can make up for experience, but there are many people with serious eye injuries at the school of hard knocks. If you don't know what you are doing, don't do it and find some one that can help.