9-Way 850W Power Supply Roundup

Efficiency Testing

Unlike past reviews, we are going to break the efficiency section down into different sections ranging from the usual “Off” tests to the load tests.


Off


The nine PSUs we tested here seem to cover the full range of efficiency when the system is turned off. It is interesting to see how some power supplies consume nearly three times the wattage as others when plugged into the same system. Of the bunch, the most surprising thing here are the two similar CWT PSH platforms in the Toughpower and Xigmatek units with a gap of about 20 percent between them. Otherwise, the XFX with its Seasonic platform is the most efficient here while Antec and Silverstone bring up the rear.


Idle


Honestly, the “Off” chart we saw before really can’t tell the real efficiency of a power supply which is why we see the order of things being totally different here. Once again though, the XFX Black Edition as the most efficient unit with the Enermax and Seasonic not too far behind which is understandable considering their 80Plus Silver certifications. We can also see that on average the standard 80Plus and 80Plus Bronze units can consume 10 to 20 watts more than the most efficient ones.


GPU / Gaming Load


In higher load scenarios, the more efficient power supplies really start stretching their legs and pull out in front of the competition. Unfortunately, the high-end Antec Signature really suffers here and posts some of the worst results by requiring 37W more to run the same test as the Revolution 85+. What was surprising is that the Andyson platform the Ultra X4 is based off of seems to be coming into its own in this test and posts slightly better results than most of the 80Plus Bronze units. The Silent Pro M from Cooler Master also does quite well here.


CPU Load


Once again, the gap between the men and the boys widens significantly. We have to remember that as the load increases, a few percent increase or decrease in efficiency can make a world of difference for your electricity bill at the end of the month. The Silverstone Strider Plus seems to be getting more efficient as the load increases as has the Antec Signature but the Thermaltake and Ultra units have seriously taken a turn for the less efficient side of things. Considering the Thermaltake claims their unit hits 80Plus Bronze levels, it is disappointing to see it being less efficient than the 80Plus Standard certified Xigmatek.


Extreme Load


Nearly 100W. Let’s say it again for emphasis: 100W. That’s how much separates the most efficient power supply in this roundup from the least efficient. We were amazed by two things here: how the Enermax Revolution is able to absolutely dominate the field (we are sure it is flirting with 80Plus Gold status here) and how poorly the high-priced Thermaltake unit performs. It is also good to see how well the Cooler Master and Silverstone units do here as well.