The CCC Catalyst Control Center, that comes with it will work as well, but your looking at clocks at least as comparable to the 5850 speed probably around 875-900Mhz core (you could probably do better but im not too familier with the card) and the memory clock you could probably set to 1400 and be safe (once again i quote what i said with the last one, you could probably get it better than that) also the the CCC monitors the Temeratures and fan speed of the card. so that you can run tests on the card in order to test the speeds.
i own the 5850 and have it clocked to 850 core clock and 1250 memory clock with temperatures that do not get past 55-60C at load.