I was reading this thread and remembered I made a chart of cooling-fan direction-actual temps....etc. Thought I would share it. Maybe it can be some assistance. I have found that higher/lower speeds make a difference (and full speed is not always the best). Anyhow, here's the pic (hope this can help with your set-up):
MB: Crosshair-V Formula-Z......CPU: FX-8350......COOLING: Corsair H80i......
RAM: Patriot Extreme 16GB-1600 MHz......GPUs: (2x) Asus GTX680 DirectCUII......
PSU: UltraX4 1050W......DRIVES: OCZ (ssd) & 2 Barracuda (hdd)......
OUTER: Corsair 650D, Asus Blu-ray,Asus DVD & touch screen fan control