A general guide to a power supply’s quality lies in its weight. This isn’t a hard and fast rule, but generally higher quality components are heavier because more metal is used in the transformers and capacitors, which generally translates into cleaner power. Heavier power supplies also tend to use larger heatsinks to disipate the heat generated in the power conversion. Taking a look inside, we can see that the Toughpower uses some high-quality components, so the weight isn’t all heatsink to compensate for cheap electronics.
Power supplies that use high quality components tend to last much longer, which counts for ThermalTake’s MTBF of 120,000 hours (over 13 years of constant operation).
Looking inside the unit reveals that the electronics have been carefully placed, and the wires routed and soldered cleanly. There are three finned heatsinks, made from standard aluminum, and the beefy electronics are more expensive Japanese parts. All rails are professionally terminated at a very clean distribution board, and the general build quality is very impressive.
The embedded 140mm fan was extremely quiet during initial testing, but became noticable at around 50% load (450 Watts). The fan is automatically voltage regulated, depending on the PSU’s load, and it runs at a quiet 5v up to 60% load. The fan’s voltage is increased to 9 volts at 80% load, and a full 12 volts at full load. At full load the fan could be heard, but wasn’t any louder than our relatively quiet test rig (which uses the quiet Zalman 9700 NT).
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ThermalTake Toughpower 850W PSU Performance
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The fluctuations of all rails were extremely tight, barely exceeding 1% variance at all load levels. The 12 volt rails were spot-on until full load, where the rails dipped down to 11.8V, but was still within a very tight variance. The 5 volt rail was slightly over-volted at all load levels, but again was within 1 percent tolerance.
The efficiency of a power supply is determined by the output power divided by the power input. Some power is always lost when converting Alternating Current (AC) to Direct Current (DC), and the loss is emitted as heat. Therefore a more efficient power supply runs at a lower temperature delta than a less effient one. The Toughpower ran over 80% effieciency at all loads, and was 85% efficient at full load.
The overall efficiency of the ThermalTake Toughpower 850W is excellent and easily exceeds the new ATX design specifications of 80% efficiency.
