To measure noise levels, the cooler or fan was plugged into a passively cooled, silent laboratory power supply, with the operational voltage set according to the manufacturer's specifications. This setup allowed us to measure the sound level of each cooler without other noises interfering. Measurements were taken 20" (50 cm) from the air discharge of the power supply. The room noise level was 31 dB (A). For adjustable coolers, we used the same settings that we did when we measured the thermal resistance.

Weight

The weight of the cooler was also taken into account in the evaluation, because a cooler that exceeds the weight specifications of AMD and Intel can lead to problems when transporting the system. If the cooler is too heavy, it has to be removed before the computer can be transported. Otherwise, there is a risk of it becoming detached from the CPU and bouncing around the inside of the PC, irreparably damaging the motherboard or other components in the process.

Guarantee

The manufacturer's guarantee should also be considered: if the CPU is damaged because a cooler with improper specifications was installed, the guarantee is often voided. For AMD Athlon XP or Sempron processors in particular, the weight of the cooler can be a problem. In these processors, the die is completely unprotected and can be destroyed rather easily if the cooler is improperly installed. Intel Pentium 4 and AMD Athlon 64/FX processors, on the other hand, are adequately protected by a heat spreader. These CPUs won't be so easily damaged by the increased pressure of a heavy cooler or a less-than-delicate installation.