Cooler Master XG PLUS 850 Platinum 850W Power Supply Review

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Load Testing

For those of you that are curious as to some of the reasoning, equipment, and how our rating system works behind our PSU testing program here at TheFPSReview, we have put together an introduction for you. This program is based on what the author developed at [H]ardOCP and utilizes the equipment bequeathed to the author by Kyle Bennett. The testing we are conducting today is exactly as described in that document and starts with our 120v, 100v, Torture, and 80 Plus Tests.

120v and 100v Load Testing Results

Cooler Master XG PLUS 850 Platinum load tests reults

Test #1 is equal to approximately 25% of the rated capacity of the Cooler Master XG PLUS 850 Platinum at 45c. This makes Test #1 equal to 220W by loading the 12v rail to 16a, the 5v rail to 2a, the 3.3v rail to 1a, the +5vsb to 2a, and the -12v to 0.3a. The results of Test #1 show the main positive DC output rails starting off above nominal. The efficiency for this unit is starting off in good shape at a value of 88.75% at 120v AC input and 88.04% at 100v AC input. We see the exhaust temperature is coming in at 48C at 120v AC input and 49C at 100v AC input.

Test #2 is equal to approximately 50% of the rated capacity of the Cooler Master XG PLUS 850 Platinum at 45c. This makes Test #2 equal to 430W by loading the 12v rail to 32a, the 5v rail to 4a, the 3.3v rail to 3a, the +5vsb to 2a, and the -12v to 0.3a. Test #2 sees results in the DC output voltages end up mixed relative to what we saw with Test #1. The largest changes are a 0.04v drop on the 12v and 5v rails. However, certain connectors on the 12v rail also saw an increase of 0.01v and the 3.3v stayed even with Test #1. The efficiency has moved up to 90.09% at 120v AC input and 89.34% at 100v AC input. We see an exhaust temperature of 50C at 120v AC input and 52C at 100V AC input.

Test #3 is equal to approximately 75% of the rated capacity of Cooler Master XG PLUS 850 Platinum at 45c. This makes Test #3 equal to 635W by loading the 12v rail to 48a, the 5v rail to 6a, the 3.3v rail to 4a, the +5vsb to 2a, and the -12v to 0.3a. Test #3 sees the main DC output voltages drop once more. The 5v and 3.3v rails drop by 0.01v each. The 12v rail drops by up to 0.04v. The efficiency in Test #3 moves down to 89.31% at 120v AC input and 88.19% at 100v AC input. We see an exhaust temperature of 53C at 120v AC input and 55C at 100V AC input.

Test #4 is equal to approximately 100% of the rated capacity of the Cooler Master XG PLUS 850 Platinum at 45c. This makes Test #4 equal to 848W by loading the 12v rail to 68a, the 5v rail to 2a, the 3.3v rail to 2a, the +5vsb to 2a, and the -12v to 0.3a. In the final regular test, we see the 12v rail move down by up to 0.1v. The minor rails also drop by 0.01v on the 3.3v rail or 0.02v on the 5v rail. The efficiency has dropped as we see it come in at 87.97% at 120v AC input and 86.62% at 100v AC input. We see an exhaust temperature of 60C at 120v AC input and 64C at 100V AC input.

Torture Test

Cooler Master XG PLUS 850 Platinum torture test results

The Torture Test is equal to approximately 80% of the rated capacity of the Cooler Master XG PLUS 850 Platinum at 45C. This makes the Torture Test equal to 668W by loading the 12v rail to 50a, the 5v rail to 7a, the 3.3v rail to 5a, the +5vsb to 2a, and the -12v to 0.3a. At the end of the Torture Test, the XG PLUS 850 Platinum is still doing well. The DC output voltages are generally in line with what we have been seeing in the 120v load tests. The efficiency also seems to be doing well at 89.36% with an exhaust temperature of 66C.

80 Plus Load Testing Results

Cooler Master XG PLUS 850 Platinum 80plus test results

As we see here, the Cooler Master XG PLUS 850 Platinum posts efficiency values of 88.50%-89.56%-87.20% efficient using 80 Plus’ load testing parameters. This puts the unit under the 80 Plus Platinum standards (90%-92%-89%) across the board. The biggest deviation is 2.44% at 50% load. However, we do use different equipment than 80 Plus for our testing and there is always a bit of component variation.

Load Testing Summary

The Cooler Master XG PLUS 850 Platinum did a very good/excellent job in our initial load testing. When we look at the voltage regulation, we see that the XG PLUS 850 Platinum had peak changes of 0.1v on the 12v rail, 0.04v on the 5v rail, and 0.01v on the 3.3v rail. These absolute values are easily in the specification and excellent overall. In relative terms, this unit was mixed with the Enermax REVOLUTION DF 850W, ASUS ROG THOR 850W, SilverStone DA850 Gold (barely), and MSI A850GF.

When we look at the efficiency values posted today, this is where things go from excellent to not so much. The efficiency values ranged from 87.97% to 90.09% efficient at 120v AC input and 86.62% to 89.34% efficient at 100v AC input. During the Torture Test, the efficiency level was very nice at 89.63%. Where things went wrong was the 80 Plus test. In every one of the load tests the XG PLUS 850 Platinum missed the 80 Plus Platinum requirements. Not be a little either. The worst miss was 2.44% at 50% load! Lastly, the exhaust temperature peaked at 60C at 120v AC input, 64C at 100v AC input, and 66C during the Torture Test. With, generally, good starting results in today’s testing let’s move on to the Transient Load Tests to see what this unit will do there!

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REVIEW OVERVIEW

Voltage Regulation
9
Transient Load Regulation
7.5
DC Output Quality
8.5
Efficiency
6
Noise
8.75

SUMMARY

The Cooler Master XG PLUS 850 Platinum is the newest contender to come across our test bench and turned out to be a very good 850W power supply. The Voltage regulation and Transient Load testing results that are very good/excellent as well as competitive with other premium offerings we have seen. However, when we got to the DC Output Quality and Efficiency, while doing well in absolute values the XG PLUS 850 Platinum was not as competitive as we would like or, in the case of the DC Output Quality, is no where near rated values. If you can get this PSU on a deal, at a good price, these things can be over looked.
Paul Johnson
Paul is a long time PC hobbyist and tech enthusiast having gotten his start when he broke his first C64 quickly followed by breaking his first IBM XT. Most notably however, for 12 years, he served as the Power Supply Editor for one of the truly early, groundbreaking, and INDPENDENT PC enthusiast sites ([H]ardOCP) until its mothballing in April of 2019. Paul now brings the same flair and style of his power supply reviews to The FPS Review.

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The Cooler Master XG PLUS 850 Platinum is the newest contender to come across our test bench and turned out to be a very good 850W power supply. The Voltage regulation and Transient Load testing results that are very good/excellent as well as competitive with other premium offerings we have seen. However, when we got to the DC Output Quality and Efficiency, while doing well in absolute values the XG PLUS 850 Platinum was not as competitive as we would like or, in the case of the DC Output Quality, is no where near rated values. If you can get this PSU on a deal, at a good price, these things can be over looked.Cooler Master XG PLUS 850 Platinum 850W Power Supply Review