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.
Our hold-up time result is very long since the bulk caps of both modules are utilized in this test. On top of that, we need to see a large number for a smooth transition to take place from one module to the other in case of a failure.
For details on our inrush current testing, please click here.
The inrush current is quite low with 115V input, while it's on the high side with 230V (still, we see less than 50A).
Load Regulation And Efficiency Measurements
The first set of tests reveals the stability of the voltage rails and the Twins 500W's efficiency. The applied load equals (approximately) 10 to 110 percent of the PSU's maximum load 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 0.1A. 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||Fan Noise||Temps (In/Out)||PF/AC Volts|
|1||2.337A||1.995A||1.988A||0.990A||49.75||67.540%||8233 RPM||53.8 dB(A)||37.05°C||0.939|
|2||5.726A||3.001A||2.990A||1.190A||99.74||78.498%||8782 RPM||55.3 dB(A)||38.99°C||0.970|
|3||9.471A||3.515A||3.514A||1.395A||149.84||82.945%||8844 RPM||55.6 dB(A)||39.16°C||0.978|
|4||13.224A||4.034A||4.009A||1.600A||199.79||85.260%||9124 RPM||55.2 dB(A)||39.44°C||0.986|
|5||16.646A||5.052A||5.029A||1.805A||249.74||86.466%||9294 RPM||54.9 dB(A)||39.89°C||0.989|
|6||20.082A||6.090A||6.055A||2.015A||299.71||87.120%||9609 RPM||54.7 dB(A)||40.52°C||0.991|
|7||23.524A||7.126A||7.084A||2.225A||349.72||87.371%||9836 RPM||52.2 dB(A)||41.14°C||0.993|
|8||26.992A||8.180A||8.127A||2.436A||399.76||87.408%||10316 RPM||50.4 dB(A)||41.98°C||0.994|
|9||30.915A||8.711A||8.673A||2.440A||449.73||87.406%||10718 RPM||51.6 dB(A)||42.88°C||0.995|
|10||34.551A||9.248A||9.192A||3.075A||499.67||87.196%||11062 RPM||52.5 dB(A)||43.90°C||0.996|
|11||38.834A||9.258A||9.211A||3.078A||549.61||87.074%||11556 RPM||54.8 dB(A)||44.62°C||0.997|
|CL1||0.099A||16.026A||16.004A||0.004A||131.32||75.947%||14706 RPM||53.5 dB(A)||43.43°C||0.976|
|CL2||41.624A||1.004A||1.003A||1.002A||507.25||88.205%||11013 RPM||52.5 dB(A)||44.03°C||0.996|
Load regulation at +12V is satisfactory, but it's quite loose on the minor rails. Apparently, the frame's DC-DC converters need some modification in order to offer tighter voltage outputs.
Efficiency under light loads is pretty low because the output of two PSUs is combined, doubling their power losses. Moreover, under high ambient temperatures, both fans are quite loud. We also notice a fan bearing noise in the 8000-10,000 RPM range. For those of you who weren't expecting such high acoustic readings, remember that this is a server-class PSU running under tough conditions. In addition to costing more money, professional power supplies delivering increased reliability and redundant functionality also tend to be loud. If you don't want a noisy PC, stay away from this FSP offering.
FSP Guardian Screenshots
You will find several screenshots of the FSP Guardian software below.