Cross-Load Voltage Stability
The PSUs are both immaculate in this test. Every voltage is within 2% of the required level (as promised by Seasonic for the same PSUs it sells under its own brand) and even within 1% throughout most loads.
The +12V voltage is the most stable with both PSUs. It’s always within 1% with the AX860. The AX760 only allows that voltage to exceed the 1% limit at near-maximum loads.
Output Voltage Ripple
The two PSUs were almost identical in this test, so we only show you the results of the senior model.
The high-frequency voltage ripple is noticeable on every power rail but always stays within the norm.
The low-frequency voltage ripple (at the double mains frequency) is weaker.
Temperature and Noise
The PSUs are cooled by a Sanyo Denki San Ace 120 fan (part number: 9S1212F404; rated speed: 2200 RPM) which is well-known to us by Seasonic’s Gold- and Platinum-certified products. It features a well-balanced impeller and makes little noise. The fan is partially covered with a piece of plastic to optimize air flows.
We tested the cooling system in both available modes: Normal and Hybrid.
In the Normal mode each PSU had its fan working at about 800 RPM throughout a long range of loads. The AX760’s fan began to accelerate at loads of 600 watts and higher whereas the AX860’s fan did the same at a load of 700 watts.
At full load the fans of the AX760 and AX860 worked at 1310 and 1430 RPM, respectively. The high-quality fans employed here are not uncomfortable at such speeds.
In the Hybrid mode the fan doesn’t work at all until loads of 450-550 watts but there is one unpleasant thing about its behavior afterwards. It can occasionally accelerate to 1600 RPM at loads far from maximum, which is audible even with a Sanyo Denki San Ace 120.
So if you prefer to have a quiet PSU at most loads, the Normal mode may be more appropriate. But if your computer works at loads corresponding to the passive cooling mode or if you’ve got other loud sound sources at high loads, the Hybrid mode is surely preferable.
Efficiency and Power Factor
The AX760 was 92.5%, 93.5% and 91.7% efficient at the reference loads of 20%, 50% and 100%. Its peak efficiency of 93.9% was observed at a load of 305 watts.
The AX860 was 91.9%, 94% and 92.6% efficient at loads of 20%, 50% and 100%, respectively. Its peak efficiency of 94.1% was observed in a load range of 370 to 425 watts.
The power factor of each PSU was close to 99% at high loads.
The two PSUs performed similarly in this test. We can see no problems with their standby source.