It is finally over!! I received my tiny payment of 0.01 BTG from the pool and immediately sold it before its price dropped more. It took me more than 2 weeks to mine that amount! I'm not sure I did everything the right way, I simply followed instructions on bitcoingold.org site. From this experiment I can tell that the following combination is definitely a no-go:
A few moths ago I tried mining Ethereum with the same hardware - just for test - and achieved 0.005 ETH for 5 days on minergate :)
I'm done with mining experiments for now, will continue mining AEON and sell it for STEEM to power up my account