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.
Litecoin mining with 280x/290 was a blast. I had my 290s flashed to 390 firmware which "unlocked" them and increased the hashrate. I think the wattage was above 200w per card and you had free house heating from the rig. Those cards were power hungry AS FUCK. Good times
I was mining Ethereum on these cards and it was profitable at the end of 2015. Before this, these video cards were used in mining other shitcoins, the names of which are now difficult to remember. But electricity was very cheap and there was no control over consumption in private houses and apartments.