Load Regulation, Hold-Up Time And Inrush Current
To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units.
Primary Rails And 5VSB Load Regulation
Load Regulation testing is detailed here.
Our hold-up time tests are described in detail here.
The registered hold-up time surpasses the ATX spec's minimum, so the SuperNOVA 650 P2 passes the hold-up test. We didn't have any doubt that it wouldn't; Super Flower uses a large bulk cap for this unit's capacity.
For details on our inrush current testing, please click here.
The inrush current is pretty low with 115V and 230V input. Super Flower might have used a large bulk cap, but it also implemented a suitable NTC thermistor to efficiently suppress inrush current during the PSU's start-up phase.
Load Regulation And Efficiency Measurements
The first set of tests reveals the stability of the voltage rails and the PSU's efficiency. The applied load equals (approximately) 10 to 110 percent of the maximum load the supply can handle, in increments of 10 percentage points.
We conducted two additional tests. During the first, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 0.10A. This test reveals whether a PSU is Haswell-ready or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails.
|Test #||12V||5V||3.3V||5VSB||DC/AC (Watts)||Efficiency||Fan Speed (RPM)||Noise (dBA)||Temps (In/Out)||PF/AC Volts|
Voltage regulation is good on all rails; only Seasonic's high-end Platinum-rated platform manages to outperform EVGA's offering. The 650 P2 also proves to be highly efficient, although it doesn't manage to clear the 80 Plus Platinum requirements with 50 and 100 percent of its maximum-rated-capacity loads. We should stress, however, that we tested the PSU under much harsher conditions than the 80 Plus organization uses. On top of that, the unit was within 0.5 percent of its required thresholds. With this we can assume that under normal conditions, the PSU won't have a problem satisfying the Platinum requirements.
Still, we don't think an operational temperature of 23 °C is realistic inside of a typical chassis. Since we want to push the PSUs we're testing to their limits, we continue to crank up the heat inside our hot-box. When it comes to evaluating PSUs, high ambient temperatures can separate the good ones from the rest.
As far as noise output goes, the small EVGA unit is dead silent up to the 70 percent load test; its fan started to spin faster only after passing that point. We had to overload the PSU in order to make the fan rotate at full speed. And even under those conditions the noise wasn't bad compared to other power supplies we've reviewed. ECO mode lasts quite a while, which means that in a typical machine, the fan will barely spin.