7970 crossfire feels like underperforming, need good benchmarks/comparison points

Thomas Watkins

Honorable
Oct 18, 2013
15
0
10,510
System : 3770k @ 4.6ghz
2x XFX 7970 black editions
750W XFX PSU
Z77 Sabertooth
8GB RAM @ 1600mhz
1x HDD
1x SSD

I feel like my cards are under performing. I'm sometimes getting FPS drops to 40 in BF4 and getting somewhat bad performance in other games
I tried valley benchmark at default settings and scored 4800.
Where can I find good comparison points for similar systems to know what to aim for? And what benchmarking software can I use to find good comparison points?
Also any help would be greatly appreciated if you see any reason that I might be getting FPS drops. I tried this system on an 850W PSU before and had similar FPS. I decided to downsize because the old PSU started making odd noises, and I calculated that I could run it with 750Ws.
Thanks!