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 PSU's hold-up time did not meet the ATX spec's requirements and the ST1500-GS failed this test. SilverStone should have used larger bulk caps, but these cost more and have a negative effect on efficiency. In any case, a PSU must have at least 16ms hold-up time (AC loss to PWR_OK) or 17ms minimum, including the "PWR_OK inactive to DC loss" delay time.
For details on our inrush current testing, please click here.
The registered inrush current wasn't as low as we expected, given the pair of large NTC thermistors that this PSU uses. However, the levels were low enough for such a high-capacity unit.
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(A/V)||5V(A/V)||3.3V(A/V)||5VSB(A/V)||PowerDC/AC(W)||Efficiency(%)||Fan Speed(RPM)||Fan NoisedB(A)||TempIn/Out(°C)||PF/AC (V)|
Load regulation definitely wasn't among the best we've seen, and at 3.3V and 5VSB, it was mediocre to bad. As for efficiency, this was rather low for a modern, high-end Gold PSU. Because of its high price tag, the ST1500-GS will have a hard time competing in this category. Although it uses modern technology, it seems this platform cannot offer the same level of performance as Super Flower's high-capacity designs. It is possible that the small dimensions of the PCB have set many restrictions on the design of this PSU. Whatever the case may be, we expected better performance in these tests, especially in terms of load regulation and efficiency.