Best I've been able to get with a radeon 7970 is between 1,500,000 - 1,700,000 PPS with the following settings:
-g -j 5 -n 4 -w 1000 -i 50000

The flags used above are explained below:

Enable GPU mining:
-g

Stats interval (in the settings above, I have stats printing every 5 seconds):
-j

Number of tests per gap per gpu run:
-n

Number of primes for sieving:
-i

Tried many different values for the -n and -i flags and actually had it around 2,000,000 PPS, but the test/s kept going to 0. I preferred stability so I adjusted the settings to lower the PPS and keep tests/s high.

A few other settings that may have an effect on PPS, just for some quick reference. These can all be seen by running the help command ./gapminer -h:
--work-items (gpu work items - default: 2048)
--queue-size (gpu waiting queue size - note: memory intensive)
--sieve-size (prime sieve size)
--shift (the adder shift)