I have been pretty successful in finding what Intel's take on Engineering Samples are as there is a plethora of stories of people being contacted and asked to send in their engineering samples. In addition, Intel has this page talking about it: Information About Engineering Sample Processors
They clearly state:
So what about AMD's engineering samples? They're readily available on eBay; yet I can't find any stories of anyone being asked to return an ES. I also can't find any page where AMD states information about the engineering samples such as if they are only provided under NDA or special loan agreements and selling/reselling is not allowed.
So the question is:
What is AMD's policy on Engineering Samples in the wild?
Is there a way to legally obtain a last generation engineering sample for benchmarking?