Silent_Buddha
Legend
Assuming you could run 4 dual gpu cards, then at 300 watts each they would consume 1200W meaning the rest of your system would have to consume over 450 to be pushing spec.
Don't forget you have to account for the efficiency of the power supply. In the US on the 110 volt lines that's generally in the range of 65 (really poor PSUs) to best case scenarios of ~90% with the most expensive and most power efficient PSUs operating in the most efficient power band (generally 50% of PSU power rating).
So best case scenario where you are not operating outside of the most efficient powerband on your PUS would up just the video cards to 1320 W. Throw in far more common 80% PSUs and not in the most optimum power band and that jumps to 1440. Throw in some of server class 1 KW PSUs which sacrifice power efficiency for clean and stable power and increases to potentially 1560-1620 watts just for that hypothetical quad card setup. And that's not including the rest of the system.
Obviously this is going into extreme ridiculous territory. But if you then add any household appliances to the loop, we're getting into some quite extreme territory. As well don't forget the monitor. With Quad cards of that capability we're probably looking at at least 1x 30" monitor or since this is ridiculous hypothetical territory 3x 30" monitors. When properly calibrated you're then looking at another ~70-160 watts for each monitor. So another 210-480 watts in the extreme case.
Enthusiasts with a system like that are also probably going to have either a high end computer audio setup like the a Klipsh or Logitech Z-5500 class system. Or just as likely a proper multichannel receiver. All of which can potentially add a significant power drain if the enthusiast gamer "cranks it up."
And god forbid if while doing all this that gamer's wife or girlfriend plugs in a hair dryer to dry her hair while watching him play. Or if he's got a HDTV and dedicated receiver for the HDTV in the same room. Or a portable air conditioner (that room is going to be HOT with all those components) or window air conditioner. Luckily during the winter it's unlikely they'll need a heater in that room.
Regards,
SB