Fractal Design Ion Gold 850W Power Supply Review

The Fractal Design Ion Gold 850W achieves a good performance for the price.

Fractal Design Ion Gold 850W
(Image: © Fractal Design)

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Protection Features

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

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OCP (Cold @ 24°C)

12V: 91.4A (129.1%), 11.861V
5V: 26.5A (120.45%), 4.928V
3.3V: 26.2A (119.09%), 3.280V
5VSB: 5.3A (176.67%), 4.886V

OCP (Hot @ 44°C)

12V: 91A (128.53%), 11.901V
5V: 25.8A (117.27%), 4.928V
3.3V: 25.5A (115.91%), 3.271V
5VSB: 5.2A (173.33%), 4.877V

OPP (Cold @ 26°C)

1097.21W (129.1%)

OPP (Hot @ 44°C)

1096.08W (128.95%)


✓ (186°C @ 12V Heat Sink)


12V to Earth: ✓
5V to Earth: ✓
3.3V to Earth: ✓
5VSB to Earth: ✓
-12V to Earth: ✓


Accurate but lower than 16ms



Surge: MOV
Inrush: NTC Thermistor & Bypass relay

The OCP triggering points are correctly set on all major rails under both cold and hot operating conditions. The over-power protection works well, too, and there is over-temperature protection crucial to any PSU. All in all, the protection features in this PSU are properly tuned. 

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.

The 3.3V rail is always lower than the other two, so everything is according to the Intel spec requirements. 

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. We calculated the deviations in each of the charts below 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 Graph

(Image credit: Tom's Hardware)

Ripple Graphs

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

Infrared Images

For this test, 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).

The main transformer area is the hottest part of this PSU, along with the heat sink that holds the primary switching FETs. In general, the Ion Gold 850W's temperatures are kept low. 

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Contributing Editor

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