The reason why this SoC is faster than HiFive Unmatched seems to be down to architectural improvements.
The one in JH7110 is the 2021Q1 version, AIUI.
Besides faster, it also added B extension.
$ cat /proc/cpuinfo processor : 0 hart : 2 isa : rv64imafdc mmu : sv39 uarch : sifive,u74-mc
I do not know why I thought it did. Possibly as U74-MC[0] supports that option.
Interestingly, I also took a look at RVA22[1], and found it requires Zbb but not the whole B.
Your /proc/cpuinfo isn't listing Z* extensions. Maybe lscpu output would be more detailed?
0. https://www.sifive.com/cores/u74-mc
1. https://github.com/riscv/riscv-profiles/blob/main/profiles.a...
