Energy And Acoustic Efficiency
While we don’t normally know exactly how much energy our system draws from a power supply, the 80 PLUS organization provides the exact data we need to calculate it within ±1% accuracy using In Win’s Power Man power supply.
An 80 PLUS Bronze rating is reflected in the much higher efficiency of In Win’s Power Man IP-S400DQ3-2 power unit. Cooler temperatures are the most likely reason for the 1% efficiency gain Cooler Master’s USP 100 gets from adding an exhaust fan, while Thermaltake’s power supply likely benefits from even cooler system temperatures in this metric.
Calculating acoustic efficiency is a little more complicated, in that we don’t have a baseline and there are no absolutes. Instead, we can only compare the average for this class of hardware to the individual results of each member of that class. Specifically, we divided the average CPU temperature for all systems by the actual CPU temperature of each system to obtain its relative temperature percentage, then divided the full system noise level for each system by the average of all systems to obtain its relative noise. Turning our cooling-to-noise ratio into a percentage is again a matter of simple division.
With the lowest noise and temperatures of a finished system, Thermaltake’s M9 takes the lead. In Win’s case wouldn’t shut over our CPU cooler, yet its second place finish is a reflection of the cooling advantages of leaving the side off a case. Cooler Master’s poor finish in its stock single-fan configuration indicates how badly the company needs to reconsider the value of the exhaust fan, yet potential buyers who have seen this result will at least know enough to add an exhaust fan on their own.
