I gave my opinion of the question of power on Fudzilla, so I'll just say this should close [some of] the gap with Intel due to their eDRAM cache, even though by then Intel would have maintained a monopoly for two generations (Haswell/Broadwell and Skylake/Cannonlake).  That said, Intel's version acts like cache for the CPU cores when the IGP is not in use, supposedly boosting performance (though I've never seen it in reviews), so I wonder what use AMD has in store for their implementation when the IGP is idle as dual-channel at any frequency would be a hindrance.  1024-bit comes off as 16-channels if implemented as system DDR4 RAM.