All test performed on tmpfs, /tmp/a mounted on /tmp/b.

UNTAR: tar xfz ../linux-3.0.tar.gz
LS: ls -lR > /dev/null
RM: rm -rf linux-3.0

VERSION         UNTAR    LS     RM
v0.4               48     1.5    5
v0.5-rc1           56     7     19
v0.5-rc1-1         54     4.1    9
v0.5-rc1-2         45     1.7	 3.4