Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Seasonic - FOCUS GX-850 | Seasonic - PRIME TX-1300 |
|---|---|---|
| Wattage | 850 W | 1300 W |
| Warranty | 10 yrs | 12 yrs |
| Efficiency | 80+ Gold | 80+ Titanium |
Between the FOCUS GX-850 and PRIME TX-1300, the FOCUS GX-850 comes out ahead in several specs, while the PRIME TX-1300 wins on wattage / warranty. Overall, the FOCUS GX-850 scores 80.3 and the PRIME TX-1300 scores 91.5 on our Mars Score.
Which should you buy?
The PRIME TX-1300 is the clear pick on raw spec strength, leading by 11.2 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.
The FOCUS GX-850 does not pull ahead on any single popular-comparison spec — its strengths sit in the spec-table groups rather than the headline advantages.
Pick the PRIME TX-1300 if you care most about wattage / warranty. Its strongest claims are wattage, warranty, efficiency. The single most decisive one: Wattage — 52.94% more. 1300 W vs 850 W.
Both ship with comparable modular, atx 3.0 / 12vhpwr, so those specs do not separate the two — focus on the differences below.
Bottom line: the PRIME TX-1300 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Which should you buy: Seasonic - FOCUS GX-850 or Seasonic - PRIME TX-1300?
Seasonic - PRIME TX-1300 leads the current Mars Score by 11.2 points.The more useful decision is the trade-off behind that result: compare wattage, efficiency against the way you will actually use the product.
Choose Seasonic - FOCUS GX-850 if…
Seasonic - FOCUS GX-850 does not lead a decisive measured field here, so choose it for price, ecosystem, design, or availability when those matter more to you.
Choose Seasonic - PRIME TX-1300 if…
Seasonic - PRIME TX-1300 has the measurable edge on wattage w, warranty years, efficiency.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Seasonic - FOCUS GX-850 wins
- No decisive advantages.
Why Seasonic - PRIME TX-1300 wins
- ▲Wattage — 52.94% more. 1300 W vs 850 W.
- ▲Warranty — 2.00 yrs more. 12 vs 10.
- ▲Efficiency: 80+ Titanium (vs 80+ Gold).
Spec comparison
Spec
| Spec | Seasonic - FOCUS GX-850 | Seasonic - PRIME TX-1300 |
|---|---|---|
| Wattage | 850 W | 1300 Wlead |
| Efficiency | 80+ Gold | 80+ Titaniumlead |
| Form factor | ATX | ATX |
Features
| Spec | Seasonic - FOCUS GX-850 | Seasonic - PRIME TX-1300 |
|---|---|---|
| Modular | full | full |
| Average noise (Cybenetics) | 30.73 dB(A) | 11.02 dB(A)lead |
| ATX 3.0 / 12VHPWR | true | true |
| Warranty | 10 yrs | 12 yrslead |