Working together with my APC SmartUPS SC 620, this PSU was stable at loads up to 385 watts when powered by the mains and could switch to the UPS’s batteries at a load of 295 watts.
While the Hiper M600, based on the same platform, performed more or less well in this test, the Vantec's cross-load characteristics are much worse.
The +12V voltage is too unstable when there is high load on the +3.3V and +5V rails.
The +3.3V voltage, which was almost immaculate with the Hiper M600, sags heavily when the load on the +12V rail grows up but does not go beyond the permissible limits.
The +5V voltage seems to be the worst one as it sags quickly as the load grows up. As a result, the PSU is unable to deliver over 70 watts across its +3.3V and +5V rails combined while keeping the voltages within the required ranges.
Thus, the Vantec ION2+ VAN-600AS is no more than just satisfactory in this test.
Output Voltage Ripple
The picture is similar to what we saw with the Hiper M600. The high-frequency voltage ripple is largely within the norm, but there are occasional voltage spikes above the permissible limits.
The same goes for the voltage ripple at the double frequency of the power mains.
Temperature and Noise
The PSU is cooled by an 11-blade 135mm Young Lin Tech fan (DFS132512H, 1700 RPM). About one fourth of the impeller is covered with a transparent piece of plastic that helps optimize air flows.
The fan starts out at a rather low speed of less than 800 RPM but doesn’t keep it for long. The fan begins to accelerate somewhat later than the Hiper M600's fan (at a load of 250 rather than 200 watts) and its top speed is somewhat lower at 1550 RPM.
Efficiency and Power Factor
The power factor is lower than average if compared to other PSUs with active power factor correction, but much higher than that of the Hiper M600 which was surprisingly poor in this test.
The Vantec ION2+ VAN-600AS is inferior to the Hiper M600 in efficiency, though. The latter, lacking 80+ certification, turned out to meet the 80+Bronze requirements Andyson’s native PSUs are certified for whereas the Vantec can only meet the basic version of that industry standard. This agrees with the manufacturer's specs, however.
The standby source copes with its job just fine. This voltage doesn't go out of the limits prescribed by the industry standards.
The Vantec ION2+ VAN-600AS can only be praised for its low noise level and good efficiency at low and medium loads. Otherwise, it is all about downsides. Its +12V rail is unstable; its +5V voltage is prone to go out of the prescribed range; its efficiency falls at high loads; its output voltage ripple is too strong; and it uses capacitors of dubious quality.