Comment by adrian_b

Like I have said, Intel Skymont is a very close match for Cortex-X4, not for Cortex-X925.

With Cortex-X925 Arm has made a big jump in core size, departing from the previous Cortex-X series, which has allowed a good increase in IPC, greatly improving the results of single-threaded benchmarks, but this has been paid by a much worse performance per area, making Cortex-X925 completely unsuitable for multi-threaded applications. Therefore Cortex-X925, like also Intel Lion Cove, is useful only when it is accompanied by smaller cores that handle the multi-threaded workloads.

So unlike with previous Arm cores, Cortex-X925 has not made Cortex-X4 obsolete, as demonstrated e.g. in MediaTek Dimensity 9400, which includes 1 Cortex-X925 to get good single-threaded benchmark scores, together with 3 Cortex-X4 to get good multi-threaded benchmark scores.

It is not clear which are the intentions of Arm for the evolution of the Cortex-X series. The rumors are that the next core configuration for smartphones is intended to be like that already deployed by Qualcomm with its custom cores, i.e. to have a big core that is 3 times bigger than the medium-size core and to use 2 big Cortex-X930 cores + 6 medium-size Cortex-A730 cores, for an even split in die area between the big cores and the medium-size cores.

For this to work well, Cortex-X930 must provide a good improvement in performance per area over Cortex-X925, because otherwise it would be hard to justify a 2+6 arrangement, when in the same die area one could have implemented a 1+9 configuration, with the same single-threaded performance, but with better multi-threaded performance.

I believe that a small SoC with only 4 Skymont cores and Xe2 graphics would provide performance, battery lifetime and cost for a smartphone that would be completely competitive with any existing Qualcomm, MediaTek or Samsung SoC.

This would be less obvious in a benchmark like GeekBench 6, where Cortex-X925 or Qualcomm Oryon L would show a greater single-threaded score, but the difference would not be great enough to actually matter in real usage. Also for multi-threaded performance measured by GB6, only 4 Skymont cores would seem to be a little slower than the current flagships, but that would be misleading, because 4 Skymont cores could run at full speed for long durations within the smartphone power constraints, while the current 8-core flagships can never run all 8 cores at the 100% performance recorded by GB6, without overheating after a short time.

An 8-core Skymont SoC would be excellent for a cheap tablet with long battery lifetime and great performance, even if again, such a configuration would be penalized by GB6, which favors having 1 huge core, like Cortex-X925, for the ST score, together with an over-provisioned set of medium-size cores, which can run all together only for the short time required to complete the GB6 sub-benchmarks, but in real prolonged usage must never be all completely busy at the same time, in order to avoid overheating.