ATX Power Supplies

The ATX power supply is specifically designed for small systems that include a limited amount of hardware. It provides slightly less continuous power and 4 voltage steps (+5V, +12V, -12V and +3.3V). For smaller systems, a power supply of this capacity is sufficient. sfx power supplies generally do not provide -5V, but this has little impact on current motherboards, after all -5V and the practical -5V ISA slot have been eliminated.