Tried his "hastyhex" binary to hex filter which claims to be faster than alternatives. In tests I ran, it was much faster than hexdump, and even faster than xxd, but was not faster than lesser known public domain code, which was about 2x faster for small files and slightly faster for large ones. See, e.g., [1]
https://github.com/skeeto/hastyhex
1. https://news.ycombinator.com/item?id=27216195
https://news.ycombinator.com/item?id=27216187