Best Thermal Compound
I've been overclocking computers for over fifteen years and I can tell you first hand that thermal compounds have come a long way in that time. They are an important component of any computer build as it can make the difference between a heatsink or water-block installation that is outstanding or one that is merely average. The compounds for this list are all non-conductive pastes so problems such as shorting out your CPU or other components will not be an issue. All of them also have very high thermal conductivity for good heat transfer as well as yielding low delta temperatures (Delta T) under CPU stress testing; delta T is the amount in degrees of temperature rise above CPU idle temperatures exhibited by the CPU when at one hundred percent load. All of the thermal compounds on my list have Delta T ratings of no more than 33 degrees Celsius. Finally, all of them are formulated to be convenient to apply and easy to clean up.
Gelid GC-Extreme Thermal Compound
Prolimatech Pk-3 Nano Aluminum Thermal Compound
Tuniq TX-4 1ml Heat Conducting Thermal Compound Paste Grease
Arctic Silver 5 Thermal Compound
ARCTIC MX-4 Carbon Based High Performance Thermal Compound
This is a top performing thermal paste from highly respected Gelid and the winner of numerous industry awards. It's rated at a conductivity of eight point five watts per meter kelvin (8.5 w/m*k) which places it at top of class. Keep in mind, it's a little thicker consistency than some of the other compounds on my list, so it's a little harder to apply, but all-in-all it's still quite acceptable. It is sold in 3.5 gram tube and comes with an applicator made of flexible plastic.
This is a best of the best thermal compound from top tier Proilmatech. This paste is fairly thick and so is a little harder to apply so it's recommended you warm the paste before applying it to ease spreading. It is rated at a top notch thermal conductivity of eleven point two watts per meter kelvin (11.2 w/m*k) which is considered excellent. It is non-corrosive and non-electrically conductive and is said require no burn-in time for top performance. Available in five gram packages, this best of class performing compound is well worth consideration if you don't mind a little more involved application process.
This fine offering from Tunig is rated at a thermal conductivity of six point five watts per meter kelvin (6.5 w/m*k) and in tests performs among the best of the best. It's sold with a hard plastic applicator and although the paste isn't hard to apply, it would be easier if the applicator were more flexible. It's non-conductive and non-corrosive, thus protecting components in your PC from damage along with a low bleed under pressure for a longer effective life. All-in-all, this is a great offering whose sole downside is not the compound itself, but the applicator that it's packaged with.
Arctic Sliver is an old and highly respected name among overclockers the world over. This is their top offering and it is known for its easy application process and its top of class performance. It uses sliver particles in its formula which has among the highest thermal conductivity of any material known to man. It has a conductivity rating of nine watts per meter kelvin (9.0 w/m*k) and testing shows its reputation is well deserved with thermal performance within one degree of the very best performing compounds. It's non-corrosive and non-electrically conductive so it won't harm computer components and is easy to remove after use.
This is a great compound from Arctic Cooling although it's a thick paste and isn't as easy to apply as some of the other pastes to make our list. It's offered in five gram packages and rated at a thermal conductivity of eight point five watts per meter kelvin (8.5 w/m*k) placing it among the best thermal pastes. In tests it performance is not quite as good as the best performing compounds but it remains near the top of the heap. It is non-conductive and non-corrosive so it won't harm sensitive PC components. If bang for your buck is one of your top priorities, this offering deserves a close look.