> bzip2 -9 -k all.tar 981.78s user 9.77s system 95% cpu 8M memory 17:16.64 total
> bzip3 -e -b 256 -j 12 all.tar 2713.81s user 16.28s system 634% cpu 18301M memory 7:10.10 total
The difference in memory usage might be worth noting: 8M v 18301M
Probably worth noting that bzip2 also did by far the worst in this. ~7x larger files than the best bzip3. Large memory use is generally required for good compression.
I'm curious how well gzip would have handled this though, as it's generally low memory too, and all the others in that list have FAR more than 8M memory used.