Noob here. I have 2 old ETH mining rigs (5 cards +6 cards - 4GB). Now, I cannot use ETH mining as cards need to be upgraded. So thinking to run Bicoin core for validation purpose. Is it profitable to run validator at home. I have free internet and free electricity at my office.
As mentioned above, Bitcoin doesn't reward you for running full node and verify block/transaction. However, since you mention
free internet/electricity, just open this website (
https://whattomine.com/coins) to see other coin which can be mined with GPU (avoid coin with uses Ethash).