AMD Ryzen 7 5800U is, according to leaked benchmarks, not too far from M1.
Now, if only AMD could bring back that ARM Zen design that they cancelled a few months before Ryzen 1st Gen...
Go beyond that and the power usage balloons quickly (won't repeat myself, see my other comment on this thread at https://news.ycombinator.com/item?id=25231798).
On laptops, more power efficiency maps directly to increased performance (turbo clocks provide higher performance in bursts or at the expense of your laptop's fans sounding like a jet turbine).
Oh yes that would rock and open up a whole new level of fault tolerance as could run real-time upon two different CPU cores in parallel, which for some workloads would add value.
Certainly adding an ARM chiplet would be cool and technically doable, though so would a RISC V core and if Nvidia buy ARM then that choice may become political.
If? Was that a typo? They have indeed [https://nvidianews.nvidia.com/news/nvidia-to-acquire-arm-for...]
Truly the goal posts are always moving.
This new one (5800U) was not yet officially announced.
For the Ryzen 7 4800U, that's just 1.8GHz. 4.2GHz which is the turbo clock blows through that limit by a lot. (of course that's for multi-core workloads)
For Ryzen 5th generation, we have this for per-core only power draw, without the I/O: https://www.anandtech.com/show/16214/amd-zen-3-ryzen-deep-di...
We can see from the graph at https://images.anandtech.com/doci/16214/PerCore-1-5950X_575p... that to reach 6.6W per core, the clock has to fall to 3.8GHz. At such a clock, Zen 3 is way behind the Apple M1 performance wise.