Edit: for relative comparison between CPUs, per core metric is the most interesting unless you also account for heat, price and many other factors. Comparing a 56-core CPU with 10-core M1 is a meaningless comparison.
For example, make -j 10, or mvn -T 10.
The speed record for building my software is held by a system with over 1k cores (a couple of seconds, compared to multiple minutes on a mid-size Threadripper).
add(1, 1) = 2
add(1, 2) = 3
add(1, 3) = 4
add(1, 4) = 5
...Or run heavy renders of complex ray-traced scenes.
Or do heavy 3D reconstruction from 2D images.
Or run Monte-Carlo simulations to compute complex likelihoods on parametric trading models.
Or train ML models.
The list of things you can do with a computer with many, many cores is long, and some of these (or parts thereof) are sometimes rather annoying to map to a GPU.
‘Rather annoying’ certainly doesn’t have to be a problem. Apple can afford to pay engineers lots of money to write libraries that do that for you.
The only problem I see is that Apple might (and likely will) disagree with some of their potential customers about what functionality is essential.
While working in rust I am most limited by single core performance. Incremental builds at the moment are like, 300ms compiling and 2 seconds linking. In release mode linking takes 10+ seconds with LTO turned on. The linker is entirely single threaded.
Fast cold compiles are nice, but I do that far more rarely than incremental debug builds. And there’s faster linkers (like mold[1] or lld) but lld doesn’t support macos properly and mold doesn’t support macos at all.
I’m pretty sure tsc and most javascript bundlers are also single threaded.
I wish software people cared anywhere near as much about performance as hardware engineers do. Until then, single core performance numbers will continue to matter for me.
The same machine does nychthemeral builds that include macOS compiles on a QEMU VM, but given that I'm asleep when that happens, I only care that the night's work is done before I get up.