ATX Specification
| Voltage | Tolerance | Minimum Voltage | Maximum Voltage |
|---|---|---|---|
| +3.3VDC | ± 5% | +3.135 VDC | +3.465 VDC |
| +5VDC | ± 5% | +4.750 VDC | +5.250 VDC |
| +5VSB | ± 5% | +4.750 VDC | +5.250 VDC |
| -5VDC | ± 10% | -4.500 VDC | -5.500 VDC |
| +12VDC | ± 5% | +11.400 VDC | +12.600 VDC |
| -12VDC | ± 10% | -10.800 VDC | -13.200 VDC |
| FSP Saga 450 | 20% | 50% | 80 % | 100 % |
|---|---|---|---|---|
| Output | 84.1W | 203W | 321W | 399W |
| Input | 97W | 235W | 382W | 486W |
| Efficienty | 87% | 86% | 84% | 82% |
ATX Tester
China made with LCD display
| Normal Voltage range | Display Voltage range | ||||
|---|---|---|---|---|---|
| Name | Type | Lower | Higher | Min. | Max. |
| +5V | 5.0V | +4.75V | +5.25V | +4.0V | +6.0V |
| -12V | -12V | -11V | -13V | -10V | -14V |
| +12V1 | 12V | +11V | +13V | +10V | +14V |
| +12V2 | 12V | +11V | +13V | +10V | +14V |
| +3.3V | 3.3V | +3.14V | +3.47V | +2.0V | +4.5V |
| +5VSB | 5V | +4.75V | +5.25V | +4.0V | +6.0V |
| PG | PowerGood | 100ms | 900ms | 0ms | 990ms |
Green and red connectors must be connected separately, because tester can measure only one connector at a time. 
Voltage indicator (± 0.1V)
LL - Low Level or not connected
HL - High Level (Max display range)
As you can see this is not exactly ATX specs.
The voltage level “+12V2” refers to the P4/P6/P8 connector only It can measure only one connector at a time.
When a 5.25“ or 3.5” or SATA connection is made, only the +12V/+5V/+3.3V indicator lights (+3.3V only for SATA) will light to show a correct voltage input.