I've got the 80mm Thermaltake smart fan that you're talking about, and I tried it on my AX-7 too. Problem was, even when I moved the sensor down between the fins and in contact with the copper core, it never would spin up much over 3500 rpm so I did not get great cooling performance. I'm getting about a 4C improvement with a 50CFM Sunon fan over the smart fan which has been moved to be a rear case fan where it works well. Since I understand your CPU runs quite hot, you'll probably want a high output fan on the AX-7.