MSI MPG A850GF 850W Power Supply Review

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DC Output Quality

For those of you that are curious as to some of the reasoning and equipment behind our PSU testing program here at TheFPSReview, we have put together an introduction for you that shares a lot of the behind-the-scenes of the program. 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 will continue with our examination of the DC Output Quality.

Control Test Graphing

This image is the blank background control test on an unused connector from our SM-8800 during the testing of the MSI A850GF. This lets us determine what the background noise looks like during testing.

120v Input

100v Input

Test #1 is equal to approximately 25% of the rated capacity of the MSI A850GF at 45c. This makes Test #1 equal to 220W by loading the 12v rails to 16a, the 5v rail to 2a, the 3.3v rail to 1a, the +5vsb to 2a, and the -12v to 0.3a. The MSI A850GF is starting off in decent shape. The 12v rails are peaking at ~20mV of ripple/noise while the minor rails are peaking at less than ~10mV of ripple/noise.

120v Input

100v Input

Test #2 is equal to approximately 50% of the rated capacity of the MSI A850GF at 45c. This makes Test #2 equal to 430W by loading the 12v rails 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 only minor changes as the 3.3v rail is coming in at ~10mV of ripple/noise, the 5v rail is coming in at ~15mV of ripple/noise, and the 12v rails are coming in at ~20mV of ripple/noise.

120v Input

100v Input

Test #3 is equal to approximately 75% of the rated capacity of MSI A850GF at 45c. This makes Test #3 equal to 636W by loading the 12v rails 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 12v rails coming in at ~20mV of ripple/noise while the minor rails are coming in at ~15mV of ripple/noise.

120v Input

100v Input

Test #4 is equal to approximately 100% of the rated capacity of the MSI A850GF at 45c. This makes Test #4 equal to 850W by loading the 12v rails 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 rails peaking at ~25mV of ripple/noise while the 5v rail is peaking at ~20mV of ripple/noise and the 3.3v rail is peaking at ~10mV of ripple/noise.

Torture Test

The Torture Test is equal to approximately 80% of the rated capacity of the MSI A850GF at 45C. This makes the Torture Test equal to 665W by loading the 12v rails 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, we see the 12v rails peaking at ~25mV of ripple/noise while the 5v and 3.3v rails are peaking at ~15mV of ripple/noise.

DC Output Quality Summary

The overall DC Output Quality of the MSI A850GF is excellent. The ripple/noise values started the day off in good shape and only grew slightly during our testing. Overall, the A850GF ended up posting a peak trace amplitude on the 12v rails of ~25mV followed by ~15mV on the minor rails. None of these values exit the ATX12v specification limits or even approach those limits. Indeed, the worst value only hit ~30% of the ATX12v specification limit. In a relative sense, this unit tied the Enermax REVOLUTION DF 850W and slightly trailed the ASUS ROG THOR 850W.

Overall then, this unit did well. While it may not be the absolute best 850W unit on the market in this regard we have seen it is not that far off. Let’s move on now and see how all of this wraps up!

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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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