On a P3 863.8 Mhz, 256 KB cache, 256 MB memory machine

ls -la cd050303.iso
-rw-r--r--  1 root root 3184640 Nov 21 18:10 cd050303.iso

time gzip -9 cd050303.iso / time gunzip cd050303.iso.gz
real    0m0.900s	user    0m0.620s	sys     0m0.050s
real    0m0.121s	user    0m0.080s	sys     0m0.020s

time bzip2 -9 cd050303.iso / time bunzip2 cd050303.iso.bz2
real    0m4.565s	user    0m4.470s	sys     0m0.050s
real    0m1.405s	user    0m1.340s	sys     0m0.060s

time 7z a cd050303.iso.7z cd050303.iso / time 7z x cd050303.iso.7z
real    0m7.463s	user    0m7.030s	sys     0m0.140s
real    0m1.197s	user    0m1.070s	sys     0m0.070s

ls -la debian-K10-hurd-i386-mini.iso
-rw-r--r--  1 root   root  37681152 Dec  9 16:22 debian-K10-hurd-i386-mini.iso

gzip -9 / gunzip
real    0m9.356s	user    0m7.780s	sys     0m0.570s
real    0m2.543s	user    0m1.120s	sys     0m0.400s

bzip2 -9 / bunzip2
real    0m57.142s	user    0m54.750s	sys     0m0.390s
real    0m19.040s	user    0m17.680s	sys     0m0.530s

7z / 7z
real    1m39.446s	user    1m36.790s	sys     0m1.430s
real    0m14.542s	user    0m13.140s	sys     0m0.750s

lzop / lzop -x
real    0m4.591s	user    0m2.790s	sys     0m0.560s
real    0m1.993s	user    0m0.270s	sys     0m0.630s

rzip / rzip -d
real    1m2.657s	user    1m0.140s	sys     0m1.860s
real    0m4.451s	user    0m3.040s	sys     0m0.920s

dact / dact -d
real    3m9.402s	user    3m6.140s	sys     0m1.680s
real    0m4.363s	user    0m3.480s	sys     0m0.670s

PPMd e / PPMd d
real    3m28.762s	user    3m25.990s	sys     0m1.520s
real    3m28.681s	user    3m26.480s	sys     0m1.500s