[adrian_b]

I do not think that I have seen any public benchmark for more than a decade that can compare ARM-based CPUs with IBM POWER CPUs.

The recent generations of IBM POWER CPUs have not been designed for good single-thread performance but only for excellent multi-threaded performance.

So I believe that an ARM CPU from a flagship smartphone should be much faster in single thread that any existing IBM POWER CPU.

On the other hand, I do not know if there exists any ARM-based server CPU that can match the multi-threaded performance of the latest IBM POWER CPUs.

At least for some workloads the performance of the ARM-based CPUs must be much lower, as the IBM CPUs have huge cache memories and very fast memory and I/O interfaces.

The ARM-based server CPUs should win in performance per watt (due to using recent TSMC processes vs. older Samsung processes) and in performance per dollar, but not in absolute performance.

[my123]

After Power9, IBM became uncompetitive multi-core performance against mainstream server CPUs - both x86 and Arm. They didn't keep up with the rise in core counts.

And the single thread side isn't that good either, but SMT8 is a quite nice software licensing trick