Last weeks headlines went back and forth about which foundry will be selected by AMD to produce wafers containing Zen based processors. After Jim Kellers departure, Mark Papermaster assured that Zen is on track for samples in 2016 and a full year of revenue in 2017. Before him pointing that out there was a comment on a LinkedIn profile, putting AMD's next gen x86 desktop processor straight into 2017.
So there are several data points of more or less official type. Let me add another one, which is based on the GCC patch publication pattern. This assumes, that there are work processes behind the patches and of course GCC related deadlines for inclusion of particular changes.
This chart shows the time delta in days between the publication of patches and the launch of a particular CPU containing a new core. For some launch dates only a month was given, so I took the last day of that month for the calculation.
The Zen bars show the timeline in months starting with publication of the specific patch. With this at hand, anyone can draw their own conclusions. The scenario of first Zen based server or desktop CPUs hitting the markets in 4Q16 doesn't seem unlikely.