🖥️ PC Components

Power Supplies (PSU): What to Look For

How to choose a power supply: calculating real wattage needs with headroom, understanding 80 Plus efficiency ratings, and matching connectors to your GPU.

Power supply PSU buying guide wattage efficiency rating

Top Picks

Corsair RM750e

Corsair RM750e

750W fully modular, 80 Plus Gold, ATX 3.0/PCIe 5.0 compliant with 105°C-rated capacitors — solid headroom for a single mid-to-high-end GPU build.

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EVGA 600 B1

EVGA 600 B1

600W, 80 Plus Bronze — a budget option sized for entry-level to mid-range builds; check your GPU's minimum PSU requirement before choosing this over a higher-wattage unit.

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What Actually Matters

Calculate total system draw, then add real headroom

Add up your GPU, CPU and other components' power draw, then choose a PSU with meaningful headroom above that total — not one sized exactly to your current parts. Headroom protects against power spikes and leaves room for future upgrades.

80 Plus rating affects efficiency, not raw capability

The 80 Plus certification tiers (Bronze, Gold, Platinum and similar) indicate how efficiently the PSU converts wall power to DC power — higher tiers waste less as heat and can run cooler and quieter, but don't by themselves mean more available wattage.

Connector types matter as much as total wattage

Confirm the PSU has the specific connectors your GPU needs (some modern high-end cards need multiple 8-pin connectors or a newer 12VHPWR/16-pin connector) — a PSU with enough total wattage but the wrong connector layout still won't work without an adapter.

Modular vs. non-modular affects cable management, not performance

Fully modular PSUs let you attach only the cables you actually need, improving airflow and case tiling. This is a convenience/aesthetics factor, not a performance difference — non-modular units work identically otherwise.

Frequently Asked Questions

How much PSU wattage do I actually need?

Add up your GPU and CPU's rated power draw plus other components, then choose a PSU with real headroom above that total rather than sizing exactly to your current build — this protects against spikes and allows for future upgrades.

Does a higher 80 Plus rating mean more power?

No — it measures efficiency (how much power is wasted as heat during conversion), not total capacity. A higher-rated PSU at the same wattage runs cooler and more efficiently, but doesn't provide more usable power on its own.

Why won't my new GPU connect to my existing PSU?

Check the specific connector types your GPU requires — some modern cards need multiple 8-pin connectors or a newer 12VHPWR connector that older PSUs may not include, even if the total wattage would otherwise be sufficient.