You must change to the directory you extracted the test suite to and then run it from that folder i.e. from terminal it would look something like this:

phoronix-test-suite Chilly$ ./phoronix-test-suite benchmark darwin
to begin the benchmark.

Just a few questions. Nexuiz runs poorly and I'm getting only 20fps average and I think I know why, because OpenGL 2.0 is disabled when the benchmark runs. Is setting OpenGL 2.0 against the Phoronix suite rules? if not how do I turn it on when my benchmark runs.