I've changed the topic.
My GPU now hit 75 degrees in Sleeping Dogs, and I've decided that I want to chuck in some more cooling fans. I have two, one is very loud (stock Cooler Master 120mm front intake fan that came with the case), and the other is just tiny (see picture).
I'm thinking about installing 3 Gentle Typhoon AP-15 1850 RPM 120mm fans - front intake, side intake (right over the GPU) and rear exhaust - and leaving the bottom intake fanless (I'm worried I'll be sucking in too much dust). The top vents don't have holes for installing a fan, it's just a mesh to let hot air blow out.
How much of an improvement can I roughly expect to see on CPU and GPU temps if I do this? My GPU fans rev up at around 70 degrees C and they make a lot of noise, would be nice to prevent that from happening.