700W to 850W PSU Group Test

Cooler Master Real Power Pro 850W

Results

Cooler Master's six 12V rails were tested in two runs, firstly 12V rails 1, 2, 5 and 6 were run, then 1, 2, 3 and 4.

Unfortunately, despite the fact that the Cooler Master is a great looking unit with a very quiet fan it consistently failed as a PSU as the load was increased. The 5V rail is predominantly used by hard drives and optical drives, but also a few motherboard components make use of it too.

With a low 5V rail you can suffer cold boot issues as your drives compete for juice when they spin up. At 100 percent load we also see a low 3.3V, and consistently throughout we have a borderline acceptable 5V standby voltage.

The efficiency of the unit is very high, with a consistent 80+ percent efficiency and high 90s percent active PFC throughout the entire test run. Having six 12V rails is great for distributing workload and they work very well in testing. If only Cooler Master had concentrated on getting the basics to work as well...

Warranty

Cooler Master offers a solid three year warranty, of which the first year is return to point of sale and in subsequent years the product is returned to Cooler Master.

Conclusion

£157 may seem a hefty sum for a PSU, but remember the Cooler Master was the most powerful PSU tested here at 850W. In comparison, the Enermax Galaxy 850W is £160, but that has the 8-pin necessary for future graphics cards. There are also much cheaper 850W PSUs also available from Etasis and OCZ, which could save you £30 or £40.

Regardless, it still has to offer something special for this kind of money and overall, despite positive initial impressions the Cooler Master fails on the one thing it's primarily designed to do: supply power within the ATX specification.