Not noted here is that the fastest RISC-V general purpose machines you can currently buy use the THead C910 core, which is:

1) Chinese

2) actually Open Source (except the vector unit): https://github.com/T-head-Semi/openc910

The fastest off the shelf RISC-V machine currently is the Milk-V Pioneer using the SG2042 SoC which has 64 C910 OoO cores running at 2.0 GHz, with 64 MB L3 cache and up to 128 GB RAM. The core, SoC, board, and PC are all made in China.

Of course this situation changes very fast. There will be several machines using SiFive's P550 cores in several months -- most from Chinese companies, or at least using Chinese SoC (SiFive's own HiFive Premier P550 board). And then at the end of the year the Milk-V "Oasis" (and others from at least Sipeed) using SiFive's P670 cores, but again in the Chinese SG2380 SoC.

There are a several US startups who started work on RISC-V core in 2021-2022 who will have much faster (Apple M1 class or better) cores, but those won't arrive in machines you can buy until 2025 or 2026.