My first 7970 came with a number of issues while booting. I had it RMA'd, the new card that just arrived reaches 750 MH/s (1225MHz core, 1375 ram, 1.07 V, 168A) with sensor readings (HWiNFO64) indicate I am pulling 193 watts (Core + RAM).  My first card would already be over 220 watts at these settings, seems either software improved or hardware improved, I used the same drivers from the end of Feb, so probably hardware changed?

How accurate are the GPU/CPU sensor readings by GPU-Z or HWiNFO64?  Would using a multimeter carefully to measure PCIE and all other power connectors on system be more accurate than onboard sensors or KILL A WATT?