My Sapphire factory OC 7950 at stock clock 950/1,250 makes around 500Mh/s. If I turn the clock up to 1,050 it makes around 600Mh/s,
FYI I run an A10-5800APU and use my onboard video as well - and it contributes an extra 100Mh/s @ 800Mhz!