FSP Hydro G PRO 850W Power Supply Review: Great Build, So-So Performance

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Protection Features, DC Power Sequencing, Cross-Load Tests and Infrared Images

Protection Features

Check out our PSUs 101 article to learn more about PSU protection features.

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Protection Features
OCP12V: 82.8A (116.95%), 11.927V 5V: 31.6A (158%), 5.011V 3.3V: 33.2A (166%), 3.255V 5VSB: 3.9A (156%), 5.028V
OPP1024.25W (120.5%)
OTP✓ (121°C @ 12V heat sink)
SCP12V: ✓ 5V: ✓ 3.3V: ✓ 5VSB: ✓ -12V: ✓
PWR_OKAccurate but lower than 16ms
NLO
SIPSurge: MOV Inrush: NTC Thermistor & Bypass Relay

The OCP triggering points on the 5V and 3.3V rails are way too high. Normally, they should be within 130%. The OCP and OPP features are properly configured and the over-temperature protection is working well. Finally, the power OK signal is accurate, but its hold-up time is lower than 16ms, which is what the ATX spec requires.

DC Power Sequencing

According to Intel’s most recent Power Supply Design Guide (revision 1.4), the +12V and 5V outputs must be equal to or greater than the 3.3V rail at all times. Unfortunately, Intel doesn't mention why it is so important to always keep the 3.3V rail's voltage lower than the levels of the other two outputs.

Fine performance here.

Cross Load Tests

To generate the following charts, we set our loaders to auto mode through custom-made software before trying more than 25,000 possible load combinations with the +12V, 5V, and 3.3V rails. The deviations in each of the charts below are calculated by taking the nominal values of the rails (12V, 5V, and 3.3V) as point zero. The ambient temperature during testing was between 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit).

Load Regulation Charts

Efficiency Chart

Ripple Charts

The lower the power supply's ripple, the more stable the system will be and less stress will also be applied to its components.

Infrared Images

We apply a half-load for 10 minutes with the PSU's top cover and cooling fan removed before taking photos with a modified FLIR E4 camera able to deliver an IR resolution of 320x240 (76,800 pixels).

We notice low temperatures here, so there is no reason for an aggressive fan speed profile.

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Contributing Editor

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