PSU wattage
The maximum continuous power output a desktop power supply unit can deliver, in watts. A correctly sized PSU runs efficiently and quietly; an undersized one shuts down under load.
PSU sizing combines CPU TDP, GPU peak draw, and headroom for transients. Modern high-end GPUs (RTX 4090, RX 7900 XTX) draw 600+ W in millisecond spikes — far above their average pull — so the PSU's transient response matters as much as the watt label.
Sizing rule of thumb
Add CPU TDP + GPU peak board power, then add 30–40% headroom. A 250 W CPU plus 450 W GPU points to an 850–1000 W PSU.
Efficiency ratings
80 Plus Bronze / Gold / Platinum / Titanium describe efficiency under load. Gold (90% at 50% load) is the modern baseline. Higher ratings cost more but save little electricity unless the PC runs at full tilt for many hours daily.
ATX 3.0 / 3.1
New PSUs ship with the 12V-2x6 connector for native NVIDIA 40/50-series support and better transient handling. Older 12VHPWR adapters are functional but more fragile.
How to use PSU wattage in a real comparison
The maximum continuous power output a desktop power supply unit can deliver, in watts. A correctly sized PSU runs efficiently and quietly; an undersized one shuts down under load. In practice, this is most useful as one part of a decision rather than a standalone quality badge. Compare it alongside the workload, room, ecosystem, budget, and ownership constraints that apply to you; the strongest published figure is not automatically the best outcome for every buyer.
What to check next
On vsMars, read together so the value has product-specific context. It is especially relevant in .
Avoid the one-number trap
Manufacturers can describe the same capability under different conditions. Compare like-for-like variants, check the unit and test condition where available, and use a head-to-head page to see whether a measurable difference is material for your own use.
vsMars presents structured catalog values to make trade-offs legible. The linked product and spec pages are the right place to inspect the underlying values before buying.