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Power Supply Unit (PSU)#

A Power Supply Unit (PSU) converts mains AC to low-voltage regulated DC power for the internal components of a computer.

Color Codes of ATX#

Color Voltage
Yellow +12.0V
Red +5.0V
Orange +3.3V
Black Ground
White -5.0V
Blue -12.0V

Additional: Green is Power-On which can be shorted to ground to start PSU.

Efficiency Rating (80 PLUS)#

80 PLUS is voluntary certification program intended to promote the efficiency of PSUs. It certifies the energy effiency at different load levels

Example:

An efficiency of 90% at 50% load means that a PSU rated at 180W (maximum delivery), will draw 100W from the wall plug in order to deliver 90W to the target device.

Non-Redundant PSU#

Cartificate 20% load 50% load 100% load
80 PLUS 82 % 85 % 82 %
Bronze 85 % 88 % 85 %
Silver 87 % 90 % 87 %
Gold 90 % 92 % 89 %
Platinum 92 % 94 % 90 %
Titanium 90 % 94 % 96 %

Redundant PSUs#

Cartificate 20% load 50% load 100% load
Bronze 81 % 85 % 81 %
Silver 85 % 89 % 85 %
Gold 88 % 92 % 88 %
Platinum 90 % 94 % 91 %
Titanium 94 % 96 % 91 %

References#

https://plugloadsolutions.com