At idle the ST85F was placed under a total load of 203 watts with a recording of 249 watts consumption being obtained from the mains. Therefore the efficiency of the ST85F at idle worked out to be 81.5%.
Increasing the load on the unit produced even more favourable results, with the ST85F managing 83.4% efficiency when being placed under a total load of 646 watts.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