its going to come from the change to DDR4 and a NVME drive rather than the cpu being any better
There's only certain amount of memory speed any particular CPU can use with full effect.
Any CPU architecture is simply designed to work with some memory bandwidth etc to avoid using resources uselessly.
Execution units capable to lot more are simply wasted resources and power consumption, if they can't be fed with instructions and data.
CPU is simply very complex thing and lots of things has to be in balance and performance increases demand now improvements in lot more things.
That's why transistor budget increase hasn't brought similar automatic performance improvements as 20 years ago:
After certain point it simply became harder and harder to improve execution units.
Also improved caching, prefetching etc are always needed get more out of execution units.
RAM is simply always so much slower than CPU's internal operation.
Where memory bandwidth helps automatically is increasing number of simultaneous worker threads. Meaning core count.
(that's why GPUs need massive memory bandwidths even at expense of some latency)
Again mass storage speed comes truly into equation only when working memory runs out.
During gameplay CPU handles data only from RAM.
And that NVMe is no substitute for enough RAM, because Flash memory is magnitudes slower than DRAM.
In fact NVMe brings very little improvement over SATA SSDs to game, or even Windows loading time, because there's so much other things going on than raw drive accesses:
https://www.youtube.com/results?search_query=nvme+ssd+hdd