Fractal Design Ion SFX Gold 500W Power Supply Review

Top performance at a reasonable price.

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Protection Features

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

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Protection FeaturesRow 0 - Cell 1
OCP12V: 58.4A (142.44%), 12.003V 5V: 28.3A (141.5%), 5.004V 3.3V: 25.5A (127.5%), 3.308V 5VSB: 6.4A (213.33%), 5.037V
OPP714.1W (142.82%)
OTP✓ (145°C @ 12V heat sink)
SCP12V: ✓ 5V: ✓ 3.3V: ✓ 5VSB: ✓ -12V: ✓
PWR_OKProper Operation

SIPSurge: MOV Inrush: NTC Thermistor & Bypass Relay

The OCP triggering point at +12V and OPP are set higher than 140% since this is a low capacity platform, so it has to have a tolerance to high power spikes that can occur if you have an energy-hungry GPU installed. There is no need, though, for a higher than 130% OCP triggering point at 5V since this rail is not heavily used for quite some time now.

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's voltage doesn't exceed the levels of the other two rails. 

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

(Image credit: Tom's Hardware)

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).

The temperatures are low, despite the operating conditions. This proves that the fan profile could be more relaxed, but as we already stated, Seasonic probably wanted to make it sure that this platform will outlive the ten-year warranty.

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Contributing Editor

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