Look at my sig... that will tell you. temps run idle around 38-41C (depending on ambient temps) and I have my chip OC'd with no worries about the fan... the 7700 is more than enought to handle it. but I will tell you this... it's big... I mean really BIG. it's about 6-7 inches in diameter to give you an idea.
and the VF-700 drops the temps like 5C right off the bat.