Depends on how many GPUs are in the PC. Circa 2011 I had quad-Radeon 6970 machines pulling ~1000w each from 1200 watt power supplies, measured with a kill-a-watt.

Those machines ran 24/7 for at least 36 months before I had to start servicing stuff like GPU fans and heat sinks.

This stuff can be designed NOT to melt the dang 6 pin 12v rail