ATX power supply units (PSUs) by wattage and efficiency. 3 products.
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Power Supply Buying Guide
Editor's Note
A power supply failure can take other components with it. The one component where you should not chase the cheapest price is the PSU. 80+ Gold efficiency is the minimum I'd recommend — it's more efficient under load, runs cooler, and the manufacturers that meet Gold certification generally have better component quality inside the unit. For a 650W Gold PSU, the Corsair RM650x and Seasonic Focus GX-650 are both reliable platforms with 10-year warranties. Size your PSU at 1.3–1.5× your system's peak load for headroom and to keep the fan quieter (PSU fans spin up under high load).
Fully modular, 80+ Gold, and zero RPM fan mode below 40% load means near-silent operation during gaming. The 10-year warranty reflects Corsair's confidence in the internals — OEM'd from a high-quality platform. At 650W it covers RTX 4070 builds with CPU headroom, and modular cables simplify cable management significantly.
⚠Buying a no-name 650W PSU to save $30 — a low-quality PSU can deliver unstable voltage that causes random crashes, or fail catastrophically and damage connected components; the PSU is not where to cut costs
⚠Undersizing for future upgrades — an RTX 4070 build needs 650W today; adding a second M.2 drive, more RAM, or upgrading to a 4080 later pushes that to 750W+; buying an 850W unit now costs $20–30 more and eliminates a future upgrade bottleneck
⚠Ignoring efficiency at your load level — 80+ Gold is rated at 50% load; at 10–20% load (idle PC), even a Gold PSU drops to 85% efficiency; Platinum or Titanium units are worth the premium only for always-on workstations or servers
For a mid-range build (RTX 4060/4070 + Ryzen 5/Core i5): 650–750W. For high-end (RTX 4080/4090 + Core i9/Ryzen 9): 850–1000W. Always leave 20–30% headroom above your system's peak draw for efficiency and future upgrades. Use a PSU calculator with your exact components to confirm.
What does 80 Plus Gold mean?
80 Plus is an efficiency certification — it measures how much wall power actually reaches your components vs lost as heat. Bronze (~85%), Gold (~90%), Platinum (~92%), Titanium (~94%). Gold is the value sweet spot in 2026: meaningfully efficient, cooler, quieter, without the price premium of Platinum/Titanium.
Is a modular power supply worth it?
Fully modular PSUs let you connect only the cables you need, improving airflow and making cable management much cleaner. Semi-modular keeps essential cables attached and detaches the rest. For most builders, fully or semi-modular is worth the small premium for a tidier, better-cooled build.
Do I need a 750W or 1000W PSU for an RTX 4080 build?
An RTX 4080 has a 320W TDP. Paired with a Core i7 or Ryzen 7 (~125W), your system draws ~500–550W under full gaming load. A 750W Gold PSU gives solid headroom and headroom for CPU boost spikes. 850W is the recommended choice for future-proofing and efficiency. A 1000W PSU is only necessary if you're pairing an RTX 4090 (450W TDP) with a high-end CPU.
How long does a power supply last?
Quality PSUs from Seasonic, Corsair, and EVGA are typically rated for 100,000 hours MTBF and carry 5–10 year warranties. In practice, a Gold or Platinum PSU from a reputable brand lasts 7–10 years in a normal build. Cheap PSUs fail sooner and can damage connected components when they do. The PSU is the one component where saving $20 by buying a lower-quality unit is not worth the risk.
What is ATX 3.0 and do I need it?
ATX 3.0 is the updated power supply spec that includes a native 16-pin PCIe 5.0 connector (600W capable) for high-TDP GPUs like the RTX 4080 and 4090. If you have an RTX 4090, an ATX 3.0 PSU with a 16-pin connector eliminates the adapter required by older units. For any GPU below the 4090, a quality ATX 2.52 PSU with adequate wattage is sufficient — the 16-pin adapter that ships with most current GPUs works without issue.
