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