Edit, back to sidecase closed. Seems the drop was temporary, as it ended up raising the temp by about 5 deg C over time. Guess the case is designed to help with airflow in mind to keep things cool.
I get a permanent performance bonus with the case open, that's why my PC is half-naked ever since I started overclocking two years ago.
I *do* still have six 80mm fans (four up front, two in the back) installed though, just to keep that lazy air a bit in motion.
Unfortunately, my case is rather badly designed. The front fans can't simply cope with the "air burn" of my CPU, because the intakes at the front of the case are way too small.
However, they do cool my HDDs pretty well.
...do these fans come with software to allow direct control over fan speed?
None that I know of, but...
Not sure if the fans will come with software to control fans, but you can get speedfan and do it.
...Joe got it right.
Normally your mainboard controls fan speed if the fan supports it (mine doesn't), but if you like to be in full charge, Speedfan is the way to go.
Honestly, I couldn't care less about noise emissions. If it's loud, it is cool and if it is cool, I am happy. :d