ATX power supplies

Buy the wattage your parts actually need, then choose on connectors, efficiency and warranty. That order matters, because a supply chosen from a rough guess is the part most likely to fail under load and take something else with it. Size it from your real parts first, then come back to this list.

Required power comes from a complete build

The 156-row public specification catalog holds units from 16 makers. Recorded capacities run from 450 W to 1600 W, with 150 ATX and six SFX units. It is distinct from the separate 47-row US ATX market-coverage reference, whose narrower manufacturer and availability evidence is preserved without merging similar names or revisions. These are boundaries of their explicit scopes, not a wattage recommendation for a particular PC or proof of current US stock. Read 26 July 2026.

The calculator does not size a supply from a partial parts list. A processor or graphics card it cannot identify stays missing rather than quietly counting as zero watts, because a supply chosen against a lower bound fails under load. Read 26 July 2026.

Fix these requirements before comparing offers

1. Complete component demand: identify the exact CPU, GPU, drives, cooling, expansion devices, and any manufacturer power guidance before choosing a capacity. A recommendation remains unavailable when a required power term is unresolved. Read 26 July 2026.

2. Physical fit: filter by ATX or SFX, then check exact dimensions and cable clearance with the case and PSU manufacturers. The list records the form factor for all 156 units but does not carry complete physical dimensions, so form factor alone cannot certify fit. Read 26 July 2026.

3. Exact connector set and revision: GPU connector information is present for 150 units, while six remain unknown. Keep the PSU revision and exact graphics-card connector requirement attached to the choice instead of inferring compatibility from wattage or product-family name. Seasonic FOCUS GX specifications, retrieved 26 July 2026 and MSI MAG A850GL specifications, retrieved 26 July 2026.

4. ATX compliance: an exact ATX version is recorded for 115 units, with 41 left unknown. Do not convert a missing compliance field into an older version or assume that two revisions of one family comply with the same standard. Read 26 July 2026.

5. Efficiency, modularity, and warranty: efficiency and modularity are present for all 156 units, while warranty length is present for 125. Compare each property separately after capacity and compatibility are resolved. A missing warranty field is unknown, not zero years. Seasonic CORE GX and be quiet! Pure Power 13 M sources, retrieved 26 July 2026 and be quiet! product page, retrieved 26 July 2026.

Specifications do not establish quality

This list is built from manufacturer product pages and manuals. It does not contain measured voltage regulation, ripple, hold-up time, transient response, protection-trip results, a licensed teardown, or an exact independent safety-certification record. Wattage, efficiency, ATX version, warranty, connector count, and brand therefore cannot be combined into a product-quality ranking from this evidence. Read 26 July 2026: source registry, reviewed 2026-07-25.

Platform identity is known for only nine of the 156 records. A family-level resemblance cannot safely fill the other 147 platform fields, and a price comparison must keep exact model and revision identity intact. Read 26 July 2026: product-identity methodology, published 2026-07-26.

What would change the price status

Each retained offer must preserve manufacturer part number, wattage, platform when known, form factor, revision, condition, merchant, source URL, and fetch time. Ambiguous revisions do not count toward price or coverage. Once the real observation window reaches 14 days, 10 usable price readings, and 60% coverage, the site can place an eligible offer within that exact PSU's observed price window. That state remains separate from system sizing and product-quality evidence, and no missing price or specification is converted to zero. Product-identity, coverage, and price-state methodology, published 2026-07-26.