How to Pick the Right Power Supply — Wattage, Efficiency, and What Actually Matters

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The power supply is the most important component nobody talks about. Every other component depends on it for clean stable power. I developed a deep respect for power delivery systems from troubleshooting electrical problems on mega yachts — the principles are the same at any scale.

How to Calculate the Wattage You Need

Add GPU TDP plus CPU TDP plus 100 watts for everything else. Add 20 to 30 percent headroom.

$500 build: RX 6600 at 100W plus Ryzen 5600 at 65W plus 100W equals 265W. Add 30 percent. Buy a 550W unit.
$800 build: RX 7700 XT at 263W plus Ryzen 7600 at 65W plus 100W equals 428W. Add 30 percent. Buy a 650 to 750W unit.
$1,200 build: RX 9070 at 220W plus Ryzen 7700X at 105W plus 100W equals 425W. Add 30 percent. Buy a 750 to 850W unit.
$2,000 build: RTX 5080 at 320W plus Ryzen 7950X3D at 120W plus 100W equals 540W. Add 30 percent. Buy a 1000W unit.

Efficiency Ratings

80 Plus Gold — the recommended minimum for any build over $600. 87 to 90 percent efficiency at typical loads.
80 Plus Platinum — worth considering for high-wattage builds where efficiency savings compound.

Modular vs Non-Modular

Fully modular PSUs allow you to connect only the cables you need. Fewer cables means cleaner cable management and better airflow. For any build over $700 a fully modular PSU is worth the modest additional cost.

Recommended PSUs by Build Budget

$500 build — Corsair RM750e (or budget EVGA 550 BR)
$800 build — Corsair RM750e
$1,200 build — Corsair RM850e
$1,500 build — Seasonic Focus GX-850
$2,000 build — Corsair HX1000i