what hashrate do you get?
I have a 7870 and get about 420~ so I suspect he pulls in closer to 550/600~.
You probably need to unlock the EULA Config VDDC. Try this guide:
http://forums.overclockersclub.com/index.php?showtopic=182403it might be out of date but I still think you need to find a method to unlock your VDDC. I believe it's locked currently.