Cortex-X4 a.k.a. Neoverse V3 has significantly lower performance per core than Zen 5.
However, Neoverse V3 has a lower die area, so you could implement more cores per socket than with Zen 5, but this has not been done yet, as these new CPUs have only 136 cores per socket versus 192 cores per socket for Zen 5.
For programs that do not use array operations, i.e. which do not use AVX/AVX-512 instructions, Neoverse V3 has better performance per watt than Zen 5. But that changes for programs that benefit from AVX/AVX-512, where Zen 5 has better performance per watt.
Moreover, Zen 5 is already old. By the end of the year there will be Zen 6, which will be the real competitor for these new Arm CPUs, and Zen 6 will have better performance per watt, even more cores per socket and even more performance per core.
>Cortex-X4 a.k.a. Neoverse V3 has significantly lower performance per core than Zen 5.
I don't quite believe that, especially per core. In SPECint2017 from David Huang [1], Zen5 (HX 370) @ 5.1 GHz boost = 9.9 points, so Zen5 is approximately 1.94 points per GHz. But
Neoverse V3 (Cortex-X4) @ 3.2 GHz = 8.2 points, so V3 is approximately 2.56 points per GHz.
Arm 64C Neoverse V3 boosts to 3.7 GHz. AMD 64C Zen5 (9575F) boosts to 5 GHz. So this rough napkin mouth would show at maximum boost Neoverse V3 is right around maximum boost Zen5.
Zen5 fares much worse at base clocks, with Arm's 64C CPU offering +40% more SPECint perf per core than Zen5 because AMD downclocks to 3.3 GHz, but Arm is still up at 3.5 GHz + huge IPC advantage.
However, Neoverse V3 has a lower die area, so you could implement more cores per socket than with Zen 5, but this has not been done yet, as these new CPUs have only 136 cores per socket versus 192 cores per socket for Zen 5.
For programs that do not use array operations, i.e. which do not use AVX/AVX-512 instructions, Neoverse V3 has better performance per watt than Zen 5. But that changes for programs that benefit from AVX/AVX-512, where Zen 5 has better performance per watt.
Moreover, Zen 5 is already old. By the end of the year there will be Zen 6, which will be the real competitor for these new Arm CPUs, and Zen 6 will have better performance per watt, even more cores per socket and even more performance per core.