Vortex12 wrote:

Any graphics card worth using seems to consume 100-200 Watts.

There are dedicated 'mining' motherboards that will take 19 graphics
cards and 3 ATX power supplies

https://youtu.be/ZM1vaHflxFE

Furthermore the it is a 3.3 volt supply that GPU's need, (the yellow
wires on your PC cable harness) so they require 30 amps or more!

Yellow wires on ATX power supplies are +12V, the orange wires are +3.3V,
and the 6 or 8 pin PCIe connectors only have +12V