[Cryptography] sha1sum speed

[Henry Baker]

I just run Linux's 'sha1sum' on a number of very large files, and the calculation took significantly longer than I expected.

'sha1sum' is only modestly faster on a very large file than copying the file.

I noticed that
1) the cpu meter wasn't pinned at 100%; and
2) multiple cores weren't being fully utilized.

BTW, I don't care about "SHA1", per se; I could just as easily have used "SHA256" or some other hash function.

Questions:

A.  Are there HW speedups today for crypto hash functions?

B.  Are there side-channel issues that are slowing down these hash functions?

C.  Are hash function speeds considered important these days?