For everyone concerned with timing, I tested compressing a 4gb image of a quad boot USB key with a variety of junk on it at compression level "4".
It still beats bzip2 by 90 mb and was almost 3 minutes quicker: # time -h bzip2 -k key.img 11m59.71s real 10m39.48s user 5.03s sys # time -h 7z a -mx=4 key.img.7z key.img 8m39.02s real 7m38.57s user 4.95s sys # ls -la | grep key -rw-r----- 1 sol wheel 4102029312 Mar 8 11:27 key.img -rw------- 1 root wheel 904489376 May 6 11:38 key.img.7z -rw-r----- 1 sol wheel 997632056 Mar 8 11:27 key.img.bz2 Best Regards, Ben Cadieux