Test:

gzip <-> bzip2
==============

nitpicker@box:~/saved/sav/test>cat bz2.*.err |awk '{R=R+$1;U=U+$3;S=S+$5}END{print "Real:"R" User: "U" System: "S }' 
Real:726.27 User: 676.47 System: 8.17
nitpicker@box:~/saved/sav/test>cat gz.*.err |awk '{R=R+$1;U=U+$3;S=S+$5}END{print "Real:"R" User: "U" System: "S }' 
Real:344.96 User: 302.94 System: 15.68
nitpicker@box:~/saved/sav/test>

-> gzip etwa 2* schneller

nitpicker@box:~/saved/sav/test>du -k 
345646  ./none
138882  ./gzip
107028  ./bzip
591812  .

bc:
===
scale=10
138882/345646
.4018041580  -> 40,2 % vom Orginal
107028/345646
.3096462855  -> 31,0 % vom Orginal

Tja..