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 BitFenix Formula Gold 550W. 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 BitFenix Formula Gold 550W at 45c. This makes Test #1 equal to 147W by loading the 12v rails to 10a, the 5v rail to 2a, the 3.3v rail to 1a, the +5vsb to 2a, and the -12v to 0.3a. The BitFenix Formula Gold 550W is starting off in excellent shape as all of the rails we monitor 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 BitFenix Formula Gold 550W at 45c. This makes Test #2 equal to 275W by loading the 12v rails to 20a, the 5v rail to 3a, the 3.3v rail to 2a, the +5vsb to 2a, and the -12v to 0.3a. Test #2 sees minor changes as the 3.3v rail is coming in at less than ~10mV of ripple/noise still, the 5v rail is coming in at ~10mV of ripple/noise, and the 12v rails are peaking at ~20mV of ripple/noise.
120v Input
100v Input
Test #3 is equal to approximately 75% of the rated capacity of BitFenix Formula Gold 550W at 45c. This makes Test #3 equal to 403W by loading the 12v rails to 30a, the 5v rail to 4a, the 3.3v rail to 3a, the +5vsb to 2a, and the -12v to 0.3a. Test #3 sees the 12v rails coming in at a peak of ~25mV of ripple/noise while the minor rails are coming in at ~15mV (5v) or ~10mV (3.3v) of ripple/noise.
120v Input
100v Input
Test #4 is equal to approximately 100% of the rated capacity of the BitFenix Formula Gold 550W at 45c. This makes Test #4 equal to 539W by loading the 12v rails to 40a, the 5v rail to 7a, the 3.3v rail to 5a, 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 minor rails are peaking at ~25mV of ripple/noise on the 5v rail and ~20mV on the 3.3v rail.
Torture Test
The Torture Test is equal to approximately 80% of the rated capacity of the BitFenix Formula Gold 550W at 45C. This makes the Torture Test equal 440W by loading the 12v rails to 31a, the 5v rail to 8a, 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 ~30mV of ripple/noise while the 5v rail is peaking at ~20mV of ripple/noise and the 3.3v rail is peaking at ~15mV of ripple/noise.
DC Output Quality Summary
The overall DC Output Quality of the BitFenix Formula Gold 550W is passing. The Formula Gold 550W ended up posting a peak trace amplitude on the 12v rails of ~30mV followed by ~25mV on the 5v rail and ~20mV on the 3.3v rail. The worst relative value among these hit ~50% of the ATX12v specification limit which is not great. While we do not have another 550W unit to compare this unit to, these results are not very compelling given what we have seen from other units to date even when we give this unit some amount of credit for being a more entry-level product. Let’s move on now and see how all of this wraps up!