Not really, they will just move to a chiplet design, well AMD already, have you seen pictures of Ryzen 3700? There is room for another chip on the die. When everyone is on 5nm and maxed out, they will just make the die bigger and add more chiplets and scale it.
IPC will probably be dead though.
AMD have themselves stated that they expect clocks to drop with the new nodes, and nothing so far indicates that either TSMC, Samsung or Intel at their new or upcoming nodes will reach 6-7 GHz. My expectations is that we are near or at the peak of clock speeds with the current type of semiconductor technology.
The new nodes will make it possible to squeeze more cores into small dies, but it will come at a cost. Firstly, the node efficiency gains alone are not enough to maintain clock speeds, and current Coffee Lake and Zen+ CPUs are already in throttle territory. The other problem with more cores is diminishing returns, as most non-server workloads are synchronized. This means that in reality adding many more cores doesn't really compensate for slower cores, in fact, with ever-increasing core count core speed becomes more important to maintain good performance scaling.
So, with clock speeds stalled once again, the future of performance scaling is pretty much depending on what we commonly refer to as "IPC". Intel's upcoming Sunny Cove/Ice Lake and Golden Cove(2021) will both feature IPC gains. The other big area of improvement is SIMD, namely AVX. Ice Lake will bring AVX-512 to the mainstream, and while Zen 2 will bring an appreciated doubling of AVX2 performance, it still lacks AVX-512 for now. AVX is in generally underutilized, which is sad, since AVX and multithreading combined scales incredible well for both vendors.
The 7nm EUV is just a different solution to reduce the manufacturing costs, as far as I know.
It's not necessarily more efficient than the current Non-EUV process.
EUV is expected to increase production speed and improve yields, perhaps even giving a small performance increase too.
Both Intel and TSMC has struggled a lot on their new nodes. It's been a year since Intel started shipping their first 10nm parts, and the volumes have been really low, and the yields I guess are embarrassingly low.
TSMC have been somewhat more successful with their "7nm" HPC node producing medium sized chips, but still unable to ship anything in volumes. I'm really curious how this is going to pan out for Zen 2, which luckily have their "chiplet" design, but I still wonder what kind of tricks TSMC may have up their sleeve, since shipping "hundreds" of chips this time is not going to cut it.
And keep in mind Nvidia did gain a lot more performance by going from 28nm to 16nm than AMD did so Radeon VII might not be the best example.
I think the point was that Vega 64 => Radeon VII is the same architecture on two different nodes, and with a roughly comparable configuration.
Maxwell => Pascal featured some architectural improvements and a large increase in shader processors, which is something Radeon VII did not.