So where it matters is low-latency, realtime processes. If you’ve ever watched your scheduler (not something most people would do, I’m a silly nerd) it bounces processes around core to core. There’s various reasons why it’ll shift a workload to another core, and outside of a kernel debugger you don’t know why but the point is it happens, and more often than you’d think.
No big deal… except there IS a small penalty when that happens. It isn’t an immediate switch. Well with everything on a monolith die, it is near enough as makes no odds, hence why it can do that. However, the more separation there is, the less true that is. This is something that has to be accounted for in actual multi-processor systems. There the scheduler will NOT move things CPU to CPU unless there’s a good reason. Likewise, programs can tell the OS that they aren’t to span NUMA nodes unless absolutely necessary because of penalties in memory access speeds.
A chiplet design is not the same thing, there’s no NUMA, all memory goes through one controller, and the internal bus is much faster than the QPI/Infinity Fabric link. But it still takes more time than moving to a different core on the same chiplet, enough that it could potentially cause hitching in time critical tasks.
Gamers found this out back in the day, that disabling one of the chiplets lead to better performance since the game wasn’t using 16 cores, and it stopped the threads from getting bounced across the chiplets. Low latency audio could likewise be affected, since there is little time to tolerate stalls.
I don’t think it is likely an issue today, at least with patched Windows 11, it has an advanced scheduler that should be aware of the chiplets and schedule accordingly, though I haven’t been able to get confirmation of that, same as it is aware of the P-cores and E-cores and schedules accordingly. Just saying it was one thing I was aware of that was an issue back when they first went to that design.
As you say, either would work well, you can’t really go wrong. CPUs are getting stupidly powerful these days and you’d need to be doing pretty huge templates before you started saying “man I could use more power” with a current gen high-end CPU.