Out of curiousity, what is the default voltage of your GPU (you may need to use Afterburner to find that out)? The reason I ask is that there are 3 different stock voltages possible for 7970s... some of them are 1.17V, some are 1.112V, and some are 1.08V (pretty sure my memory is correct on those marks).
It is common for 7970s to hit 1100-1150 MHz on the core with stock voltage, but it's never a guarantee. I'd still recommend an RMA/warranty replacement of your card since the secondary BIOS doesn't work.