Low Profile Socket-A/Socket-370 Cooler Roundup - December 2001

Testing in space-restricted conditions

The second test was done in restricted space, with only about 5mm of space (depending on the cooler) above the fan. This corresponds to the typical conditions in a 1U case. Some of the coolers from the first test did not perform well enough to cool our simulator (or a CPU with comparable power dissipation) adequately under these conditions. We aborted the test as soon as it became obvious that the tested cooler wouldn't provide adequate cooling for the simulated CPU (43W) under 1U conditions. Keep in mind that a temperature difference of 70°C means that if the case temperature is 30°C, the CPU would run at around 100°C - and no current CPU can bear this temperature. Therefore, the second graph includes only the best-performing coolers.

Under 1U conditions, the coolers typically perform much better if the direction of the fan is inversed - that is, if the fan exhausts air from the heatsink instead of blowing onto it. Only Alpha takes this effect into account; by default, their 1U cooler ships with the fan installed in an "exhausting" configuration. The fan of the C&COM Tech and the TennMax Max7 coolers can also easily be reversed; with the other coolers, this is not possible: The supplied screws were unsuitable for reversing the fan, and sometimes additional washers are required.

Cooling Performance in Restricted Space Temperature in Degrees Celsius (lower is better) CoolJag JAC311C (exhausting) (1) Alpha PAL153U (exhausting) CoolJag JAC311C (blowing) C&COM Tech S6612P-30CU (exhausting) Thermaltake TFCF014-1 (exhausting) (2) C&COM Tech S6612P-30CU (blowing) Thermaltake TFCF014-1 (blowing) 40.1 44.3 56.1 60.7 61.6 70.8 71.5 | 0 | 14 | 29 | 43 | 57 | 72 | 86