Avg fps are so unimportant in this case. See, what your minimum fps are is more interesting. bf3: the best cards reach generally about 69fps or something like that. So why should your card should perform that as well? Because it do not? Is 45-65 more 45? That should explain it. Sorry, but I do not understand, why people always add their own opinion in fps to their new gfx cards!?!
For the people it always work 10-20fps better than in officual benchmarks.
BTW: Don't forget to add additional 10-20% of the fps on every 7xxxx series (bf3 = round about 20%) - in newer benchs the ghz editions should be in front of the 680 (nearly equal). Add more speed (overclocked editions or handmade) in the 7xxx series and get another 10-20%.