Power Supply

The Standard

The latest standard: ATX 3.0 (primarily for modern powerful GPUs).

• Motherboard connector: used to be 20-pin, now 24-pin. The largest connect, goes to the motherboard.
• CPU connecter: 4-pin, or 8-pin for high-end CPUs; also goes to the motherboard.
• GPU (PCIe) connectors: 6-pin (max 75 W) or 8-pin (max 150 W) or 12-pin (max 648 W) or 16-pin (max 662 W, introduced in ATX 3.0), connected to the PCIe card.
• SATA connectors: 15-pin, connected to SATA SSD / HDD drives or optical disc drives.

Modular

A modular power supply provides a detachable cable system, offering the ability to remove unused connections at the expense of a small amount of extra electrical resistance introduced by the additional connector.

Form Factors

• The Small Form Factor with a 12 V connector (SFX12V) configuration has been optimized for small form factor (SFF) system layouts such as microATX.
• The Thin Form Factor with a 12 V connector (TFX12V) configuration has been optimized for small and low profile Mini ITX and Mini DTX system layouts.

Power Consumption

CPU

• Mainstream: 65W / 95W
• Gaming: 105W / 180W

Motherboard

25 to 40w

RAM

Unlike SSD, RAM is volatile so needs the power all the time to store the data.

• DDR1 (2.5 Volts): 4 to 5.5 W
• DDR2 (1.8 Volts): 3 to 4.5 W
• DDR3 (1.5 Volts): 2 to 3 W
• DDR4 (1.2 Volts)
• DDR5 (1.1 Volts)

Storage

• SSD: 0.6 to 2.8W
• HDD (3.5"): 6.5 to 9W

Video Card

• 100+ W