The Short Answer
For a mid-range gaming build (RTX 5070 Ti class GPU), buy an 850W ATX 3.1 80+ Gold fully-modular unit from a reputable brand: Corsair RMx, Seasonic Focus GX, EVGA SuperNova G7, MSI MAG. Spend $130-$170. For a high-end build (RTX 5080/5090), step up to 1000W.
How to Pick a Wattage
Add your CPU TDP, GPU TGP, and 100W of overhead for everything else. Then add 30% headroom for transient spikes and aging. So:
- Ryzen 9 + RTX 5080 (170W + 360W + 100W = 630W) × 1.3 = ~820W → buy 850W
- Ryzen 9 + RTX 5090 (170W + 575W + 100W = 845W) × 1.3 = ~1,100W → buy 1200W
- Core Ultra 5 + RTX 5060 Ti (125W + 200W + 100W = 425W) × 1.3 = ~550W → buy 650W
Why ATX 3.1 Matters
The 12V-2×6 connector (improved revision of 12VHPWR) is the standard for current and future high-end GPUs. ATX 3.1 PSUs ship with this connector native, support proper transient spike handling, and pass the certified “Cybenetics” testing for safety. If you’re building a system that may host a modern NVIDIA flagship, ATX 3.1 is non-optional.
Efficiency Ratings Decoded
- 80+ Bronze — Budget. Saves $50 today, costs you more over the PSU’s life in electricity. Skip.
- 80+ Gold — The sweet spot. Efficient enough that the electricity savings cover the price premium.
- 80+ Platinum — Marginal real benefit. Worth it only for systems that run heavy workloads 24/7.
- 80+ Titanium — Workstation/server tier. For most home builds, the efficiency gain isn’t worth the price.
Modular vs Semi-Modular vs Non-Modular
Fully modular is worth the small premium for any build over $1,000 — cable management is easier, swaps are easier, and you don’t ship dead weight. Semi-modular (main 24-pin and CPU cables fixed) is fine for budget builds. Non-modular is a no in 2026.
Brands to Trust
- Seasonic — Some of the best engineering in the industry
- Corsair RM/RMx/HX series — Excellent middle ground
- EVGA SuperNova G/GP/GT — Top-tier reliability
- be quiet! Pure Power/Straight Power/Dark Power — Excellent and very quiet
- MSI MAG/MPG — Strong recent showings
- FSP, NZXT C-series — Solid mid-range
Brands to Avoid
Any PSU under $50 from an unbranded or low-reputation manufacturer. These units commonly fail their own ratings, have inadequate transient protection, and can damage other components when they fail. The phrase “I saved money on a PSU” precedes the most expensive computer failure stories.
Warranty Length as a Quality Signal
PSU warranty length correlates strongly with quality:
- 3 years or less — Avoid
- 5 years — Acceptable
- 7 years — Good
- 10+ years — Premium tier
The 12VHPWR/12V-2×6 Connector Safety Story
If you’ve seen the news about melted GPU connectors, here’s the reality: the original 12VHPWR (ATX 3.0) had real engineering issues, particularly with bent cables and insufficient pin retention. The updated 12V-2×6 (ATX 3.1) addresses the worst of these problems. Best practices:
- Use the cable that came with your PSU, never an adapter from older PSUs
- Ensure the connector is fully seated (you should hear and feel a click)
- Don’t bend the cable within 35 mm of the connector
- Avoid extreme cable angles inside the case