![[H]ardOCP](/images/blank.gif){kind=small}
- Date:
- Thursday , December 10, 2009
- Author:
- Paul Johnson
- Editor:
- Kyle Bennett
- Google +1
XFX Black Edition 850W Power Supply Review
XFX jumps into the PSU market at the 850 watt mark which has proven to be the toughest watermark for many manufacturers when it comes to building a truly outstanding power supply. We have seen many fail here. Can XFX pull it off and continue to diversify its product lines while keeping the trust of the enthusiast?
Ripple Testing
Since voltage output is not the only concern when it comes to quality DC output we next examined the ripple and regulation characteristics of the XFX Black Edition 850W. We examine these points since unnecessary ripple can cause premature failure of sensitive components in a number of different PC subsystems.
The DC output quality was logged via our digital oscilloscope and the EasyScope II software package. Each divider horizontally represents 2ms while each divider vertically represents 0.05v or 50mv. The ATX specification states that a unit should remain at or below 120mV of ripple and noise on the 12v rail while under 50mV on the 3.3v/5v rails.
Control Test Graphing
This image is the blank background control test on an unused connector from our SM-8800 during the XFX Black Edition 850W testing. This lets us determine what the background noise looks like during testing. If at any time a trace deviates from this reading that is the noise/ripple being logged by the oscilloscope for that rail. As you can see the trace is flat and shows as a blue line obscuring the axis. If during a test the axis becomes visible but a waveform is hard to discern it is most likely due to the amplitude of the trace being small in relation to our voltage divider.
120v and 100v Input
Test #1 is equal to approximately 25% of the rated capacity of the XFX Black Edition 850W at 45c. This makes Test #1 equal to 218W by loading the 12v rail to 16a, the 5v rail to 1a, the 3.3v rail to 1a, the +5vsb to 2a, and the -12v to 0.5a. The results of Test #1 are excellent all around. The 12v rail is peaking at just ~10mV of ripple/noise while the minor rails are coming in at below 10mV of ripple/noise.
Test #2 is equal to approximately 50% of the rated capacity of the XFX Black Edition 850W at 45c. This makes Test #2 equal to 425W by loading the 12v rail to 32a, the 5v rail to 3a, the 3.3v rail to 2a, the +5vsb to 2a, and the -12v to 0.5a. Test #2 sees little if any change in amplitude of any of the traces as ~10mV continues to be the ceiling for this unit.
Test #3 is equal to approximately 75% of the rated capacity of the XFX Black Edition 850W at 45c. This makes Test #3 equal to 639W 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 0.5a. Test #3 sees the 12v rail increase slightly to ~15mV of ripple/noise but the minor rails are still coming in below 10mV.
Test #4 is equal to approximately 100% of the rated capacity of the XFX Black Edition 850W at 45c. This makes Test #4 equal to 841W by loading the 12v rail to 68a, the 5v rail to 1a, the 3.3v rail to 1a, the +5vsb to 2a, and the -12v to 0.5a. In the final regular test the 12v rail tacks on another ~5mV to hit ~20mV of ripple/noise. The minor rails however have not moved at all and still are below 10mV.
Torture Test
The Torture Test is equal to approximately 80% of the rated capacity of the XFX Black Edition 850W 45c. This makes the Torture Test equal to 671W 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 0.5a. In the Torture Test we see almost identical results to what we saw in Test #4 as the 12v rail is peaking at ~20mV while the minor rails are still below 10mV of ripple/noise.
DC Output Quality Summary
The DC Output Quality of the Seasonic M12D-850 was excellent, so that would roughly make the results for the XFX Black Edition 850W double excellent! 
Where the Seasonic unit peaked at ~35mV of ripple noise for its 12v rails, the single 12v rail of the XFX peaked at just ~20mV or 1/6 of the ATX12v specification limit. Oh yeah, it was that incredibly smooth. The minor rails were as well behaved proportionally as they did not even hit 10mV of ripple noise at any point during testing. These results easily beat most other units we have seen and are almost unheard of in this DC output capacity as the M12D-850, Antec Signature 850, and Corsair HX850W were three of the best we have seen in this regard up to this point and all of them did worse than this unit. That makes this a simply outstanding result for the Black Edition 850W. Well done XFX!