GPU power requirements and PSU sizing

A GPU's board power (also called TBP, total board power, or TDP depending on the manufacturer) is the sustained draw the card is rated for under a full load, not its peak. Modern cards spike briefly above that figure during transient load changes, such as the start of a benchmark run or a scene transition, and it is those spikes a PSU has to absorb without tripping its protection circuitry.

That is why the manufacturer-recommended system wattage is always well above the card's own board power: it is sized for the card's spikes plus a full gaming CPU, motherboard, storage and fans, not for the card in isolation.

These are the system wattages NVIDIA and AMD publish for popular cards this site currently tracks, alongside each card's own board power for comparison. The figure without a manufacturer recommendation is a CompareYourGPU estimate, marked as such.

Every card's own specification page on this site states its board power and its recommended PSU wattage, sourced the same way as the figures above. If you want to sanity-check that figure, or size a PSU for a system that is more than just the graphics card, add up board power for the GPU, a typical 65-125 W for the CPU depending on tier, and a further 100 W of headroom for storage, fans and RGB.

Treat the result as a floor, not a target. Buying a PSU rated exactly at your calculated draw leaves no margin for an older unit that has degraded, a future upgrade, or a spike the calculation did not account for.

The 80 PLUS rating on a PSU states its efficiency at converting wall power into DC power at 20%, 50% and 100% load, not how much power it can deliver. A more efficient unit wastes less as heat, which means a quieter fan curve and a lower electricity draw for the same GPU load. The tiers, from lowest to highest efficiency, are Bronze, Silver, Gold, Platinum and Titanium.

For a system built around a high-power current-generation card, Gold is generally the practical minimum: the difference in running cost and heat over the PSU's lifetime is larger than the price gap to Bronze, especially if the system runs under load for extended periods.

Two things stop an otherwise-compatible power supply from working with a new card: total wattage, and connectors. Current high-end NVIDIA cards use a single 16-pin 12V-2x6 connector; many older power supplies do not include one natively and ship an adapter from multiple 8-pin connectors instead, which is a legitimate way to run the card but is worth checking for before ordering.

The wattage printed on the PSU's own label is its rated continuous output, not a number you can exceed briefly the way a GPU's board power can be exceeded. If your current PSU is within roughly 100-150 W of what the new card plus the rest of your system needs, budget for a new PSU rather than assuming it will be fine.