The Swiftech MC462 continues to be the heaviest cooler tested. It weighs in at 789 grams, making it seven times heavier than the cheap serial fan.

The correlation between a cooler's weight and its cooling capacity and efficiency is a direct result of the materials used to manufacture it. While gold, silver and copper are remarkable heat conductors, they are also very dense: hence the coolers' impressive total weight. Furnished with a solid copper plate, the Swiftech MC462 weighs in at almost 800 grams! AMD's guidelines only allow for a total mass of 300 grams maximum, however, if the cooler is to be affixed to the socket using metal clamps. Among the new coolers we tested, there were some models that weigh in at well over 400 grams. The heaviest of these is the Global Win CAK 38 with a solid copper heat sink, weighing in at 500 grams. And even the Zalman CCC-Project and the Blizzard Thunderbird are anything but light. The Global Win CAK 38 draws some flak for its classic CPU clamp; it really should have special screws to attach it to the motherboard. You have no choice if transporting your PC - you have to remove the fan. Leaving it attached could seriously damage the CPU.