Rustls Multi-Threaded Performance Is Battering OpenSSL

The Rustls project as a modern TLS library written in the Rust programming language and an alternative to the likes of the widely-used OpenSSL and Google's BoringSSL has published some new performance figures. When looking at the multi-threaded server performance of Rustls, its performance is typically outperforming BoringSSL by a significant margin and downright dominating over OpenSSL.

The Rustls project last week posted some new benchmarks looking at the multi-threaded server performance of BoringSSL, OpenSSL, and Rustls atop Debian 12 running on an Ampere Altra Q80-30 processor.

There were some staggering wins for Rustls especially in relation to OpenSSL:

The results are performance per thread, so the flat line is ideal performance as seen with Rustls and BoringSSL up through the 80 physical cores on this ARM64 server processor. OpenSSL meanwhile battles scalability problems.

For those interested see more benchmarks of their OpenSSL vs. BoringSSL vs. Rustls multi-threaded performance comparison on rustls.dev. If interested I have also begun benchmarking Rustls on different CPUs.