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.