AMD 2016 Zen CPU Speculations

[sulblazer]

For clarity, the 40% ipc increase of the Zen is over that of the Excavator chip line. The excavators are suppose to have a higher ipc than the steamrollers which in turn is higher than the piledrivers (the AM3+ fx chip line). Can anyone make an educated guess at roughly how much of the supposed IPC increase is the Zen over the Fx line then?