Tokenization performance is complicated, but your guidepost is that the institutions with the resources and talent to do so choose to write extremely fast tokenizers: sentencepiece and tiktoken both pay dearly in complexity (particularly complexity of deployment because now you've got another axis of architecture-specific build/bundle/dylib to manage in addition to whatever your accelerator burden always was: its now aarch64 cross x86_64 cross CUDA capability...)

Sometimes it can overlap with accelerator issue, but pros look at flame graphs: a CPU core running the AVX lanes hard isn't keeping the bus fed, million things. People pre-tokenize big runs all the time.

I don't know why this thread is full of "nothing to see here", this obliterates the SOTA from the money is no object status quo: I'd like to think better of the community than the obvious which is that C++ is threatening a modest mindshare comeback against a Rust narrative that's already under pressure from the explosion of interest in Zig. Maybe there's a better reason.