The Zippy Emacs was placed under a load of 646 watts. This counts for a total of 107% of the power supplies rated output. At this load, the power supply required 764 watts from the mains to produce the 646 watts required by our custom made power supply tester. Therefore the efficiency of this power supply can be found by a simple equation: (646 / 764) * 100 that works out to be an efficiency rating of 84.5%.Noise Testing
Possibly the hardest part of any PSU review is summarising the level of noise given out by the unit. The threshold for what is considered 'noisy' varies from person to person and therefore what I may consider a quiet unit, another person may consider extremely loud. A common way to resolve this issue is to use a dBA meter to measure the units noise level, however this doesn't take into account the pitch (type) of noise emitted and whether it is likely to irritate end users.
For this reason OC3D records all power supplies at idle and load in wav format for you to make your own informed decisions. All recordings are taken at 30cm away from the PSU and outside of a PC case. You will need to remember that noise levels will be reduced by varying amounts once the PSU has been installed inside your PC enclosure.
Idle Recording - Download
Load Recording - Download
At idle I found the GSM-6600P to be reasonably quiet. With the unit installed inside a PC enclosure, I am confident that the unit would have been inaudible.
Placing a full load on the unit caused the fan speed to increase significantly thus increasing the noise levels at the same time. Despite the load recording above sounding quite high-pitched, I was pleasantly surprised with the way in which the GSM-6600P controlled the 80mm fan, keeping noise levels as low as possible.