It seems the results are correct, I was searching around for anyone who benched a 7970 at the exact same presets (maxed everything), and had a hard time finding one with a single 7970... but found GTX 680 results (at Ultra quality vs High on yours)
and these are only slightly slower than yours.
Let's see if anyone with a 7970 can chime in and bench Heaven at the same settings
edit: You might also want to look for benchmark results with a single 7970 and match their settings to see if you get the same results.