I posted a reference 7950 BIOS a few pages back, search for it and try it. Its for a 8950 technically but I think it worked for some other individual's 7950.
Yeah that's what I used with 987mv and -9 power limit and just 925/1250 to run at 125h/s with not much more wattage than stock. You can push the core and memory higher and get a little more but it is almost not worth it imo. On a Sapphire though not MSI..