> Solid Silicon S1 […] will be the CPU powering Raptors upcoming
> Blackbird II & Talos III series (klick).

Yes, see comment #240 :-)

> looks like Power ISA 3.1C does not deprecate any features over the
> POWER9 so it should run G4/G5/POWER9 built code just fine.

I'm not sure if S1 will implement 3.1C or an older/newer specification. What we know at least is that Power11 will necessarily implement the same ISA spec as Power10 (see comment #248), which should be 3.1B.