I get the same ~ 580mk\s
OK Thank you for the test.
With the optimizations suggested by arulbero , with few memory transfer improvements, by adding specific GPU intrinsic (notably the funnel shift that should improve SHA and RIPE performance), I hope to reach 1GK/s on your config.

Waiting for a new version

Will there be settings like Bitcrack in the future?
-i, --in FILE
Read addresses from FILE, one address per line. If FILE is "-" then stdin is read
--keyspace KEYSPACE
Specify the range of keys to search, where KEYSPACE is in the format,
START:END start at key START, end at key END
START:+COUNT start at key START and end at key START + COUNT
:END start at key 1 and end at key END
:+COUNT start at key 1 and end at key 1 + COUNT