Cross-Load Voltage Stability
The Seasonic X Gold series is, unfortunately, far from perfect in terms of output voltages. Although it meets the industry requirements, its results in this test are worse than what we can expect from PSUs with dedicated voltage regulation. In every X Gold series PSU we’ve tested so far, at least one voltage was 4% off the required level.
The Corsair PSUs turned out to be somewhat better than their Seasonic counterparts, though.
The AX650 is the best one in this test. Its voltages deflect no more than by 3%. And it is only at low overall loads that the +12V and +3.3V voltages can be more than 2% off the required levels.
The 750W Corsair is almost as good as its junior cousin, but has a larger 3% zone on the +12V rail. It keeps all of its voltages within 3% of the required levels, too.
The highest-wattage model is the worst of the three. Its voltages can get 4% off the required levels on the +12V and +5V rails. This can only occur at unrealistic loads, though. Its voltages are going to be within 3% in the typical load range.
Output Voltage Ripple
The Corsair PSUs have similar results in this test.
The highest-wattage model has the strongest high-frequency ripple, but easily meets the industry requirements anyway.
The medium model has the strongest voltage ripple at the double frequency of the mains, but meets the industry requirements, too.
These results are excellent, just as we have come to expect from Seasonic's advanced PSU platforms.