In particular, does it support all the common crypto accelerator CPU instructions? How does it fare on the microbenchmarks the various openssl forks ship?
https://jbp.io/2019/07/01/rustls-vs-openssl-performance.html
I'm pretty sure current versions of rustls are faster than the ones from 2019, but I don't have an intuition for how OpenSSL performance has evolved in the past three years.
I'd like to do another comparison some time soon.
(Yes, the underlying ring crypto library should take advantages of specific instructions available on common CPU architectures.)