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 Photon-1200's hold-up time easily surpasses the minimum allowed by the ATX spec.
For details on our inrush current testing, please click here.
The inrush current that our shiny, new power meter (N4L PPA1530) measured is very high, especially with 115V. Sirfa should make the necessary changes to fix this.
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 supply's maximum 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 isn't bad, but it's not top-notch, either. Let's call it somewhere between good and bad. Compared with the more expensive PSUs in this category, the Photon-1200 doesn't score well. The supply does deliver its full power for prolonged periods, even at operating temperatures close to 50 °C (122 °F). However, this result wasn't achieved without problems, as you will see from the ripple results we measured. So, if you're building a power-hungry system with this PSU, keep its operating temperature below 40 °C (104 °F).
The situation gets worse when we start looking at noise output. Even at light loads, high ambient temperatures cause the fan to get really loud. Also, as you can see from the table above, it has significant bearing noise at around 1600 RPM where its acoustic output peaks. The inefficient platform doesn't leave room for a more relaxed fan profile.