I also wanted to include Linus' sha1 in our software at work. But the GPLv2 license was incompatible. Too bad it is just just in the public domain. I grabbed Steve Reid's public domain code from 1999 and ran it. It produced the same output. I ran it on a 3GB input file, and Linus' code from 2009 takes 37 to 40 seconds. (Just reading the file in the same 4k buffers only takes 3 seconds so disk reading does not dominate the time.) When I ran Steve's old version on the same input it was taking just 36 or 37 seconds. So it is slightly faster. Have compilers improved? I am using gcc 4.4.7-17. -- View this message in context: http://git.661346.n2.nabble.com/Linus-sha1-is-much-faster-tp3448007p7657473.html Sent from the git mailing list archive at Nabble.com.