Yes, Graphics cards are backwards compatible so gen 2 gpu will work on gen 1. It would be the same as running a gen 2 card at 8x in terms of bandwidth, so for this reason, I don't recommend running the best gpu in gen 1 (anything worth more than 150).
Yes, Graphics cards are backwards compatible so gen 2 gpu will work on gen 1. It would be the same as running a gen 2 card at 8x in terms of bandwidth, so for this reason, I don't recommend running the best gpu in gen 1 (anything worth more than 150).