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 hold-up time we measured falls short of 17ms. We expected this to be the case, give the bulk capacitors' low capacity.
For details on our inrush current testing, please click here.
The inrush current with 115V input is normal. It's too high with 230V input, though.
Load Regulation And Efficiency Measurements
The first set of tests reveals the stability of the voltage rails and the HPT650M’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 compatible with Intel's C6/C7 sleep states 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||PSU Noise||Temps (In/Out)||PF/AC Volts|
|1||3.563A||1.963A||1.960A||0.986A||64.784||86.016%||708 RPM||17.1 dB(A)||40.10°C||0.818|
|2||8.124A||2.951A||2.948A||1.183A||129.288||89.963%||708 RPM||17.1 dB(A)||40.63°C||0.931|
|3||13.089A||3.450A||3.433A||1.385A||194.383||91.334%||705 RPM||17.0 dB(A)||41.25°C||0.963|
|4||18.063A||3.949A||3.952A||1.588A||259.618||91.690%||705 RPM||17.0 dB(A)||41.52°C||0.976|
|5||22.715A||4.947A||4.955A||1.792A||324.904||91.537%||705 RPM||17.0 dB(A)||42.15°C||0.982|
|6||27.312A||5.949A||5.963A||1.998A||389.439||91.085%||723 RPM||17.9 dB(A)||42.67°C||0.986|
|7||31.986A||6.955A||6.976A||2.206A||454.768||90.384%||945 RPM||26.2 dB(A)||43.18°C||0.987|
|8||36.666A||7.963A||7.996A||2.414A||520.083||89.698%||1143 RPM||31.5 dB(A)||43.84°C||0.988|
|9||41.746A||8.476A||8.505A||2.418A||585.017||89.008%||1300 RPM||35.2 dB(A)||44.39°C||0.989|
|10||46.774A||8.990A||9.045A||2.524A||649.762||88.218%||1472 RPM||38.2 dB(A)||45.53°C||0.989|
|11||52.200A||9.000A||9.064A||2.526A||714.604||87.365%||1653 RPM||41.1 dB(A)||46.59°C||0.989|
|CL1||0.143A||14.003A||14.001A||0.000A||119.277||86.023%||815 RPM||21.2 dB(A)||42.12°C||0.931|
|CL2||54.179A||1.002A||1.002A||1.000A||665.503||88.532%||1462 RPM||37.9 dB(A)||45.32°C||0.989|
Load regulation on the +12V rail is satisfactory, since it lands within 1%. However, the HPT650M still can't compete against other high-end, similar-capacity PSUs in this discipline. The minor rails (especially 3.3V) aren't as tight. The same goes for the 5VSB rail, though at least it falls within spec.
The fan spins at very low speeds, even under tough conditions. We have to push the PSU beyond its limits for the fan to exceed 40 dB(A).
At the same time, none of the efficiency levels we measured satisfy the 80 PLUS Platinum standard's requirements. Then again, we test at high ambient temperatures, causing efficiency to take a hit. The 80 PLUS organization performs its certifications at 23°C (±5°C), which is an unrealistic temperature to expect inside of a chassis.
MORE: Best Power Supplies
MORE: All Power Supply Content