FSP Hydro PTM Pro 1200W Power Supply Review

To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units. 

Primary Rails And 5VSB Load Regulation

The following charts show the main rails' voltage values recorded between a range of 40W up to the PSU's maximum specified load, along with the deviation (in percent). Tight regulation is an important consideration every time we review a power supply because it facilitates constant voltage levels despite varying loads. Tight load regulation also, among other factors, improves the system’s stability, especially under overclocked conditions and, at the same time, it applies less stress to the DC-DC converters that many system components utilize.

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Results 1-8: Load Regulation

Load regulation is within 1% on the 12V and 5V rails. Still, the competition performs notably better. 

Hold-Up Time

Put simply; hold-up time is the amount of time that the system can continue to run without shutting down or rebooting during a power interruption.

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Results 9-12: Hold-Up Time

Thanks to the large bulk caps, the hold-up time is very long. The power ok signal is also accurate.

Inrush Current

Inrush current, or switch-on surge, refers to the maximum, instantaneous input current drawn by an electrical device when it is first turned on. A large enough inrush current can cause circuit breakers and fuses to trip. It can also damage switches, relays, and bridge rectifiers. As a result, the lower the inrush current of a PSU right as it is turned on, the better.

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Results 13-14: Inrush Current

The inrush current is low with both voltage inputs. 

Leakage Current

In layman's terms, leakage current is the unwanted transfer of energy from one circuit to another. In power supplies, it is the current flowing from the primary side to the ground or the chassis, which in the majority of cases is connected to the ground. For measuring leakage current, we use a GW Instek GPT-9904 electrical safety tester instrument.

The leakage current test is conducted at 110% of the DUT's rated voltage input (so for a 230-240V device, we should conduct the test with 253-264V input). The maximum acceptable limit of a leakage current is 3.5 mA and it is defined by the IEC-60950-1 regulation, ensuring that the current is low and will not harm any person coming in contact with the power supply's chassis.

Very low leakage current. 

10-106% Load Tests

These tests reveal the PSU's load regulation and efficiency levels under high ambient temperatures. They also show how the fan speed profile behaves under increased operating temperatures.

The PSU couldn't deliver 110% of its max-rated power, so we had to apply a bit lower load, at 106%. It looks worse, though, because it couldn't handle our CL2 test, where we apply full load at 12V and minimum load on the minor rails. This was a huge letdown. Even at lower temperatures, we weren't able to run a full CL2 test, since the PSU stopped after a short period. 

20-80W Load Tests

In the following tests, we measure the PSU's efficiency at loads significantly lower than 10% of its maximum capacity (the lowest load the 80 PLUS standard measures). This is important for representing when a PC is idle with power-saving features turned on.

The efficiency levels in this load range are not high. 

2% or 10W Load Test

Intel plans on raising the ante at efficiency levels under ultra-light loads. So from July 2020, the ATX spec will require 70% and higher efficiency with 115V input. The applied load is only 10W for PSUs with 500W and lower capacities, while for stronger units we dial 2% of their max-rated-capacity.

The PSU cannot exceed 70% efficiency with 2%, of its max-rated-capacity, load. 

Efficiency & Power Factor

Next, we plotted a chart showing the PSU’s efficiency at low loads, and loads from 10 to 110% of its maximum rated capacity. The higher a PSU’s efficiency, the less energy goes wasted, leading to a reduced carbon footprint and lower electricity bills. The same goes for Power Factor.

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Results 15-18: Efficiency

We would like to see higher efficiency under light and super-light loads. 

5VSB Efficiency

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Results 19-20: 5VSB Efficiency

This is one of the most efficient 5VSB rails that we have encountered so far. 

Power Consumption In Idle And Standby

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Results 21-22: Vampire Power

Vampire power is high, especially with 230V input. 

Fan RPM, Delta Temperature, And Output Noise

All results are obtained between an ambient temperature of 37 to 47 degrees Celsius (98.6 to 116.6 degrees Fahrenheit).

The fan speed profile is not aggressive. Still, it allows the fan to operate at high speeds under tough conditions because the PSU's PCB is small, so high airflow is required to keep the thermal load in control, despite the platform's high enough efficiency levels. 

The following results were obtained at 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit) ambient temperature.       

Passive operation lasts for quite long, under normal operating temperatures. Average noise output is kept low, close to 27 dBA. 

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