How to choose a power supply for a PC build

Verify the exact unit's form factor, connectors and documented suitability for your planned parts.

Illustrative image

Step 01

List the planned parts

Start with the exact CPU, graphics card, motherboard and storage configuration, plus any expected upgrades. Consult their current manufacturer documentation for power and connector requirements.

Step 02

Check the physical format

Confirm the case accepts the power supply's form factor and length. Leave room for cables and nearby drive cages where the case manual warns of interference.

Step 03

Count real connectors

Verify motherboard, CPU and graphics-card power connectors on the specific power supply model. Do not infer them from the brand, wattage or a product-family name.

Step 04

Review model-specific evidence

Look for credible independent testing of the exact model when available, with the tested revision noted. A higher wattage label is not, by itself, evidence of better quality.

Step 05

Allow sensible margin

Choose a unit with appropriate capacity for the complete system and plausible upgrades, without treating unused wattage as a performance feature. Confirm the manufacturer's operating and warranty terms.

This guide explains a decision process. It does not contain product rankings, benchmark results or hands-on measurements. How we research

Components
A practical checklist for choosing PC components
What each part is responsible for, and the support lists, slot configurations and clearances to check for each one.
Upgrades
What to check before upgrading your graphics card
Check whether a new card fits your case, gets the power connectors it needs and addresses the problem you actually see.
PC Builds
How to plan a PC build around your workload
Start from your games, applications and display target, then check CPU support lists, BIOS versions, GPU clearance and PSU connectors before you buy.