E8400 Temp variable from one chip to another?

My question is, are there differences from chip to chip in the native heat generation of the same model CPU? I assembleld my System in the spring of 2007 using an BTF-90 HSF which didn't perform to the specs shown in the Frosty Tech review, but it was within 5 deg.C across the board idle/load. I decided this May to try a different HSF to see if I could cool it down a bit. I'm currently using the Xigmatic Red Scorpion and AS5. This cooled it down about 1 or 2 deg. from the BTF90 but still not up to the listed spec on Frosty tech review for this unit. I'm currently running 45/47C idle and as high as 61/64C when gaming, now with the case side off and a fan blowing in to it. No OC. Ambient 28-30C by infrared sensor aimed at case surface.