I have a Gigabyte GTX 660 Ti 2 WAY SLi config and a 750W PSU, which is more than enough, and I can say that games nearly double their performance. I was tempted to upgrade to a single powerful GPU solution but I chose the sli configuration due to a very good airflow and cable management and my powerful PSU. Never going over 75C with the cards while gaming and a smooth and outstanding performance on max quality on the latest most demanding games such as Battlefield 4, Call of Duty Ghosts, Crysis 3. SLi has become a reliable configuration!