http://www.pcgamer.com/amd-exec-describes-threadrippers-dummy-dies-as-basically-rocks/

In response to the hoopla surrounding Threaderipper and its four dies, two of which are non-functional, or "dummy dies" as AMD calls them, an AMD exec took to Twitter to clarify things. According to James Prior, AMD's Senior Product Manager, the two so-called dummy dies are "basically rocks" and cannot be enabled.

The confusion over Threadripper started when renowned overclocker der8auer delidded a Threadripper processor last month and discovered four dies, just like AMD's server-based Epyc chips. AMD asked him to remove the video from YouTube, and then explained to him and the rest of the world that two of the dies on Threaderipper are dummy dies included for structural stability.