Start with the system, not the wattage badge
A suitable power supply must cover sustained system demand, short transient loads, connector requirements and a reasonable upgrade margin. Estimate the CPU and GPU first, then include the remaining components and avoid treating peak advertising figures as continuous capability.
Check the platform and connectors
Confirm the exact ATX specification, native GPU cable support, EPS connectors for the motherboard and protection features documented by the manufacturer. Efficiency certification describes a measured efficiency band; it is not a complete quality score.
Buying checklist
- Verify the exact model and regional SKU.
- Check the warranty and the seller handling it.
- Allow headroom without buying an unnecessarily oversized unit.
- Never reuse modular cables from another PSU model unless the manufacturer explicitly confirms compatibility.