Check the whattomine.com if what altcoin is more profitable to mine with your rigs since your electricity is free you can earn without paying electricity].
Try to mine etherium with your card use claymore.
try follow this guide
https://bitcointalk.org/index.php?topic=2126975.0Thanks for your advice.
I have no experince about mine eth. How about minimum payout, so how long we will get first payout from pool? Why almost all coin use xmr tittle for miner?