I never mined bitcoin with gpus but I mined Litecoin / dogecoin which was scrypt algo and it was very power hungry.

Back then psus were expensive and capacity wasn’t as high as today. The best bang for the buck was a 750Watt PSU. So I had a rig which basically only had 2 Gpus inside it and it was pulling 700 watts. So pretty much at capacity.

With ETH mining, I think with the same Psu I was able to mine with 4 gpus. Crazy how much power they used.