For the 5 years I've been making PC's, I had never used an aftermarket cooler. My overclocks would be mild at best (300 mhz max) and always at stock voltage with stock hsf. My new computer (e6850 3.0ghz, 8800gt) I tried overclocking from 3.0 to 3.6. I did so on stock hsf and my temps were at 65C max under load. Not bad.
Except I was using old Core Temp. My temps were actually around 80C. Oh ****. I immediately stopped overclocking and ran at stock. At stock using the RIGHT Core Temp version, after about 15 minutes of prime95 my CPU would be at 66-68C. Made me a bit uncomfortable. Taking the case off would lower it a few C, because I have not-so-good airflow (one 120mm intake, one 120mm outake, intake had dust filter). I decided that I don't care how useless 3.6 ghz is vs 3.0 for gaming (pretty much all I do on my comp), I WANTED 3.6 because I know I could.
So I simply ordered an Arctic Cooling Freezer 7 pro. As I type this I am running prime95 stable for 2+ hours at 3.71ghz.
Check out the temperature differences:
Stock HSF at 3.0 ghz : 67C
Freezer 7 Pro (MX-1 thermal paste pre-applied) at 3.7 ghz : 61C.
Keep in mind my airflow SUCKS, I have only a mid-tower, and I have an 8800GT which ejects warm air into the case and not out the back like a dual slot. My HSF has also only been installed for about 5 hours so the thermal paste hasn't had time to cure. According to the AC website my temps should go down 2-3C by the third or fourth day.
HUGE difference. Holy crap. I plan on replacing my intake fan with a much stronger but even quiter scythe and this should lower my temps a bit. And ****, it was so easy to install; didn't have to undo my motherboard.