I'm havening a fan sped problem i just replaced my stock fan on my Q9300 with a http://www.newegg.com/Product/Product.aspx?Item=N82E168.... The thing is my cpu is actually running hotter allot hotter it went from 45c idle to almost 52 c idle. I think the problem is the fan speed it says 500-3400 rpm +- but every application i use says the fan is only going to like 1000 rpm max , if my cores are running so hot why isnt my system increasing the fan speed.
It may be set on auto in your BIOS. If you can disable auto-fan speed feature for your CPU fan, it will most likely run at top speed all the time. This may be loud.
There are also a plethora of programs out there that will allow you to set custom fan profiles, so that you can retain the auto feature, not have full speed noise all the time, but run cooler than it is now.