thought I'd mention something about stock coolers.
The Stock cooler and the CPU it is included with are part of a set.
AMD and Intel put warranty's on that set. "Stock" has come to mean "crap" but in reality the Stock cooler is more then sufficient for the CPU at it's stock speeds. It wouldn't make sense to package an inferior cooler and have more warranty claims would it?
Additionally, I don't believe the CPU warranty extends to the use of third party coolers.
Just thought I'd mention that.
I did a passmark score when I first got this PC but I forget what it was. 800 or so, I think, not sure. Haven't run 3dmark.
One of the reasons you might be seeing better performance is if it's a clean installation of windows, it's amazing what a difference that can make.