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

Tom's Hardware Verdict

The FSP Hydro Pro G 850W uses high-quality parts, and a hefty warranty supports it. But its performance is lags behind the competition, and it's only quiet under very light loads.


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    Full power at 47 degrees Celsius

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    Top build quality

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    Good transient response at +12V

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    Efficient 5VSB rail

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    Fully modular

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    2x EPS and 6x PCIe connectors

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    Fluid dynamic bearing fan

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    Selectable semi-passive operation

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    10-year warranty


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    Overall performance isn't great

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    Aggressive fan profile

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    High OCP on the minor rails

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Specifications and Part Analysis

FSP's Hydro G Pro 850W has terrific build quality, but performance-wise it has stiff competition from the likes of Corsair with its RM850 and RM850x units, along with Seasonic's similar-capacity Focus Plus Gold model. Moreover, the Hydro isn't exactly quiet; its overall noise output is within the 30-35 dB(A) range, so it gets a Cybenetics LAMBDA-S++ rating.

The MSRP  for this unit is set at $139, which is justified given the quality parts that it uses, and FSP will release this PSU line to the US first, with the EU market to follow. If you are after great build quality and increased reliability, the HG2-850 fits the bill. But if you also want top performance in all areas and super-quiet operation, you should look elsewhere.

The Hydro G Pro looks to be the successor of the FSP Hydro G line. Instead of a number or version scheme, FSP decided to add the word "Pro" to the model description. The Hydro G Pro line consists of four members, with capacities ranging from 650W to 1000W. All of them are fully modular, come with fluid-dynamic bearing fans and are supported by a semi-passive operation for low noise under light loads. Finally, FSP speaks of 100% Japanese caps in these units, but this isn't enough for us. We want to know the model numbers exactly because not all Japanese caps are of the same quality.

The FSP Hydro G Pro power supply, which we will evaluate today, is 80 PLUS Gold certified, while in the Cybenetics scale it earns an ETA-A rating (88-91% overall efficiency). In the noise output section, it definitely isn't whisper-quiet, with a Cybenetics LAMBDA-S++ noise badge. This is disappointing, as there are similar spec PSUs with much lower noise output (like the Corsair RM850x).


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Manufacturer (OEM)FSP
Max. DC Output850W
Efficiency80 PLUS Gold, ETA-A (88-91%)
NoiseLAMBDA-S++ (30-35 dB[A])
Modular✓ (Fully)
Intel C6/C7 Power State Support
Operating Temperature (Continuous Full Load)0 - 50°C
Over Voltage Protection
Under Voltage Protection
Over Power Protection
Over Current (+12V) Protection
Over Temperature Protection
Short Circuit Protection
Surge Protection
Inrush Current Protection
Fan Failure Protection
No Load Operation
Cooling120mm Fluid Dynamic Bearing Fan (MGA12012XF-O25)
Semi-Passive Operation✓ (Selectable)
Dimensions (W x H x D)150 x 85 x 150mm
Weight1.7 kg (3.75 lb)
Form FactorATX12V v2.4, EPS 2.92
Warranty10 Years

Power Specifications

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Max. PowerAmps202070.82.50.3
Total Max. Power (W)850

Cables and Connectors

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Modular Cables
DescriptionCable CountConnector Count (Total)GaugeIn Cable Capacitors
ATX connector 20+4 pin (600mm)1118-22AWGNo
4+4 pin EPS12V (700mm)2218AWGNo
6+2 pin PCIe (650mm+150mm) 1218AWGNo
6+2 pin PCIe (500mm+150mm) 2418AWGNo
SATA (520mm+150mm+150mm+150mm)1418AWGNo
SATA (500mm+150mm+150mm+150mm)1418AWGNo
SATA (500mm+150mm) / 4-pin Molex (+150mm+100mm)24 / 418AWGNo
SATA (500mm+150mm) / 4-pin Molex (+150mm) / FDD (+150mm)12 / 1 / 118-22AWGNo
AC Power Cord (1370mm) - C13 coupler1118AWG-

All cables are long, and the distance between the peripheral connectors is sufficient, with the only exception being a pair of 4-pin Molex connectors. Moreover, the amount of cables is considerable given the PSU's capacity. With two EPS and six PCIe connectors, you won't have a problem powering a potent gaming station. Finally, the single FDD connector should be replaced with a 4-pin Molex, since those connectors are rarely used nowadays. It would be much better if an FDD adapter was provided instead, for users that might need it.

Component Analysis

We strongly encourage you to have a look at our PSUs 101 article, which provides valuable information about PSUs and their operation, allowing you to understand better the components we're about to discuss.

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General Data
Manufacturer (OEM)FSP
PCB TypeDouble Sided
Primary Side
Transient Filter4x Y caps, 2x X caps, 2x CM chokes, 1x MOV, 2x Gas Discharge Tubes
Inrush ProtectionNTC Thermistor & Relay
Bridge Rectifier(s)2x HY GBJ2506 (600V, 25A @ 100°C)
APFC MOSFETS2x Infineon IPA60R180P7 (650V, 11A @ 100°C, 0.18Ohm)
APFC Boost Diode1x STMicroelectronics STPSC6H065 (650V, 6A @ 110°C)
Hold-up Cap(s)1x Nippon Chemi-Con (450V, 680uF, 3,000h @ 105°C, KHS)
Main Switchers2x STMicroelectronics STF28N60M2 (650V, 14A @ 100°C, 0.15Ohm)
APFC ControllerInfineon ICE2PCS02
Resonant ControllersChampion CM6901T2X
TopologyPrimary side: Half-Bridge & LLC converter Secondary side: Synchronous Rectification & DC-DC converters
Secondary Side
+12V MOSFETS4x Toshiba TPHR8504PL (40V, 150A @ 25°C, 0.85mOhm)
5V & 3.3VDC-DC Converters: 6x Diodes Incorporated DMN3009SK3 (30V, 60A @ 70°C, 5.5mOhm) PWM Controllers: ANPEC APW7159C
Filtering CapacitorsElectrolytics: 5x Nippon Chemi-Con (1-5,000h @ 105°C, KZE), 1x Rubycon (3-6,000h @ 105°C, YXG), 5x Rubycon (6-10,000h @ 105°C, ZLH), 2x Rubycon (6-10,000h @ 105°C, ZLJ) Polymers: 30x United Chemi-Con
Supervisor ICSITI PS223H (OCP, OTP, OVP, UVP, SCP, PG)
Fan ModelProtechnic Electric MGA12012XF-O25(120mm, 12V, 0.52A, Fluid Dynamic Fan)
Fan ControllerAPW9010
5VSB Circuit
RectifierCET CEF04N7G FET(700V, 4A @ 25°C, 3.3Ohm) & PFC P15L50SP SBR (50V, 15A)

What steals attention here, to the trained eye at least, is the quality of the bulk cap. Not only it is 450V rated, but it also has a rated lifetime of 3,000h @ 105 degrees C. The majority of power supplies, even high-end ones, use 2,000 hours at 105 degrees C bulk caps, so the HG2-850 has an edge here. The quality of the caps on the secondary side is at very high as well. Besides electrolytics, many polymer caps are also used.

On the primary side, a half-bridge topology is utilized, along with an LLC resonant converter. This is typical stuff for high efficiency.

On the secondary side, four Toshiba FETs handle the +12V rail's load regulation, and a pair of DC-DC converters generate the minor rails.

The soldering quality is good. Moreover, there are many interesting parts on this side of the board.

At the front side of the modular board, many polymer caps are used as an extra ripple suppression filtering layer.

The cooling fan is of high quality, and it is powerful. A larger fan should be used though, to provide the same airflow at lower speeds (and with less noise).

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Contributing Editor

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