I've been having this question a long time. An ES cpu has a QDF starting with Q and a production unit has an SSPEC starting with S. This shows correctly in HWINFO. But it does not seem to match up with the "Prod. Unit" or "Eng. Sample" after it.
For example, the E5-2698B v3 in picture 2 has an...
Shown in the pic bellow. It seems that the window size is only good for 6 cores, the rest of cores went out of the box :(
Also for some reason memory SPD information can't be detected. In fact CPU-Z can't detect it as well, got any idea about this?