FSP Hydro PTM 750W PSU Review

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Load Regulation, Hold-Up Time & 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.

Hold-Up Time

Our hold-up time tests are described in detail here.

The hold-up time is close to 23ms, while FSP's power-good signal is accurate.

Inrush Current

For details on our inrush current testing, please click here.

The inrush currents are kept under control using both voltage inputs.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the HPT750M'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.

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Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan SpeedPSU NoiseTemps (In/Out)PF/AC Volts
14.427A1.985A1.962A0.996A74.77186.472%865 RPM25.2 dB(A)38.38°C0.989
29.910A2.977A2.954A1.200A149.75390.290%865 RPM25.2 dB(A)38.64°C0.996
315.754A3.488A3.470A1.405A224.84191.467%865 RPM25.2 dB(A)38.93°C0.998
421.607A3.990A3.960A1.610A299.69591.728%865 RPM25.2 dB(A)39.19°C0.998
527.129A4.991A4.970A1.820A374.61491.518%865 RPM25.2 dB(A)39.70°C0.999
632.660A6.016A5.984A2.030A449.55890.973%865 RPM25.2 dB(A)40.44°C0.999
738.212A7.025A7.006A2.246A524.47390.256%910 RPM27.1 dB(A)41.38°C0.999
843.780A8.058A8.032A2.457A599.47389.453%1235 RPM34.9 dB(A)42.54°C0.999
949.799A8.574A8.577A2.462A674.49488.651%1330 RPM36.9 dB(A)44.02°C0.999
1055.788A9.096A9.091A2.574A749.32687.774%1610 RPM41.7 dB(A)45.83°C0.998
1162.187A9.113A9.118A2.578A824.22586.890%1800 RPM44.7 dB(A)47.22°C0.998
CL10.098A14.026A14.005A0.004A117.93485.301%995 RPM29.2 dB(A)44.15°C0.994
CL262.448A1.003A1.001A1.001A754.54888.064%1350 RPM37.1 dB(A)45.29°C0.998

Load regulation is a little above 1% at +12V, and it's a bit looser at 5V. The 3.3V rail falls outside of the 3% range, while the 5VSB rail comes closer to 4%. There is definitely room for improvement here.

Noise is kept under control until the seventh test, and it only surpasses 40 dB(A) during the full load and overload tests when we push the HPT750M at temperatures up to 46-47°C.

We also notice a high PF, even at lower loads. FSP does a very good job with its APFC converter.

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Contributing Editor

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.