# README

crc32c is a trivial program that wraps Go's SSE4.2 accelerated CRC-32C (Castagnoli) implementation. I needed a fast checksum for amd64 that could be plonked on a number of platforms with minimal fuss. The most obvious solutions available in FreeBSD base, and its package repository, were surprisingly slow.

crc32c does not implement a check or verify mode; plumb the output into diff(1).

dmesg | grep ^CPU | head -n 1

CPU: Intel(R) Xeon(R) E-2224G CPU @ 3.50GHz (3504.34-MHz K8-class CPU)

uname -srm

FreeBSD 12.2-RELEASE-p6 amd64

time crc32c blob-1g

7ef14d22 blob-1g crc32c blob-1g 0.06s user 0.14s system 100% cpu 0.200 total

rhash is too slow.

time rhash --crc32c blob-1g

7ef14d22 blob-1g rhash --crc32c blob-1g 0.62s user 0.15s system 99% cpu 0.768 total

openssl (SHA-1) is too slow.

time openssl sha1 blob-1g > /dev/null

openssl sha1 blob-1g > /dev/null 1.16s user 0.11s system 99% cpu 1.267 total

cksfv (CRC-32) is too slow.

time cksfv blob-1g > /dev/null

cksfv blob-1g > /dev/null 2.13s user 0.28s system 99% cpu 2.415 total

cksum (CRC-32?) is too slow.

time cksum blob-1g > /dev/null