> As a good real-world benchmark, I propose you to try bzip2.
I would suggest libjpeg, for testing (2d) matrix operations.
And testing both compression and decompression
(the cjepg and djpeg utilities) on large images.
As it turned out, packing 30 MB tar file with bzip2 with various compilation options has nearly no effect -- 000, 020-60 and 060 gave me practically the same result, 020-60 and 060 were practically identical.
For story with libjpeg see another thread ;-)