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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
OCP	12V1: 36.6A (203.33%), 11.815V 12V2: 36.2A (201.11%), 11.811V 12V3: 37.7A (171.36%), 11.831V 12V4: 38.1A (173.18%), 11.844V 5V: 37.5A (156.25%), 4.994V 3.3V: 39A (162.5%), 3.268V 5VSB: 4.1A (136.67%), 4.895V
OPP	866.56W (133.32%)
OTP	✓ (174°C @ 12V heat sink)
SCP	12V: ✓ 5V: ✓ 3.3V: ✓ 5VSB: ✓ -12V: ✓
PWR_OK	Proper Operation
NLO	✓
SIP	Surge: MOV Inrush: NTC Thermistor & Bypass Relay

The OCP triggering points are sky-high in all +12V rails, most likely to be able to cope with power spikes. This defeats the purpose, though, of protecting against high currents, which can melt the cables and the connectors. The OCP triggering points are high on the minor rails, as well, and there is absolutely no reason for this because these rails are only lightly used. On the other hand, the OPP is set at a reasonable level, close to 130%, while OTP is a bit on the high side.

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.

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(Image credit: Tom's Hardware)

DC Power Sequencing Scope Shots

In all cases, the 3.3V rail is lower than the other two, so everything is fine 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

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(Image credit: Tom's Hardware)

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.

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(Image credit: Tom's Hardware)

Ripple Suppression Charts

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).

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