Well, ain't this a B.
So I built my rig back in 2009, and I got the Arctic Freezer Pro 7 cooler for my AMD X3 720 BE. It had great temps, don't recall them now. I upgraded to a 955 BE, and I got decent temps (40C idle, 57C full load) and thought, well, that is fine. Until I built my little brother's rig. I got him a 955 BE as well (we both run it stock for the time being) and the Arctic Freezer Pro 7 Rev. 2. Well, his idle is 26C and his full load is frickin 41C. What on earth!? I am about to steal his rig and give him mine. Any ideas why they are so different? Think I should reseat mine and reapply the AS5? His case is different than mine, but both have very good air flow. And everything is the same, BTW, MoBo, RAM, PSU, etc. and we were even in the same room with our rigs testing out the coolers. Ridiculous IMO, that there would be such a difference. Did he just get lucky or am I being boned or mounting mine wrong? I built both, used the same AS5 paste etc.
Well the cooler definitely does have an impact. Another aspect that could be in play is the CPU itself. It's not a secret that despite being the same model, many of them actually vary slightly. It might be the combination of both. Also, you didn't mention how long ago you last changed the paste. From what i generally learned, it is good to change it at least every year or so. So i would suggest doing that first.
That might be the case, but once he OC's it don't expect lower temps any more. Like sportsfanboy said, the new revision is meant for newer chips. However if you plan to upgrade HSFs don't look at the Arctic Freezer Pro 7 Rev. 2, it really isn't that great compared to other of its price. A better cooler (just in case you plan to upgrade your HSF later) is the Hyper 212+.
Although I agree that the 212+ is pretty great, I personally prefer the Prolimatechs or Noctuas. Yes they are pricier and yes they are huge but they do, in the end, get better cooling. Especially when you pair them in a push/pull with good fans.
But... That can be said for the Hyper 212+, not only that... Phenoms don't exactly get EXTREMELY hot, so a Hyper 212+ would do the job, after all in that review the 212+ was able to keep up with the Megahalems.
A freezer pro rev 2.0 can be great for the 775s and such ( I love mine) gets me non OC idle core temps of 25-30C in a 20-25C room, but is just not big enough for OCing the hotter chips. Remember that its only really got a 92mm fan. a 120mm quality HSF would do better, maybe not to idle temps, but load temps would see a difference.