We measure system-wide power draw from the wall while running Cyberpunk 2077 for 30 minutes. We do this at 1080p, 1440p and 2160p (4K) to give you a better idea of total system power draw across a range of resolutions, where CPU power is typically higher at the lower resolutions.
Total system power draw hits a peak of around 610W in our testing. This is done in Cyberpunk 2077, and will vary depending on the game, but as we've already seen, the RTX 4090 doesn't draw as much power as the 3090 Ti despite both sharing the same 450W-rated TGP. Either way, Nvidia recommends an 850W PSU at minimum, which seems quite sensible based on our testing.