Even in the middle of the battlefield (with explosions, smoke particles, water, avionics, shadows, moving objects, etc etc), the GPU is way below its full potential [data taken with GPU-Z during a campaign mission]:
Date , GPU Core Clock [MHz] , GPU Memory Clock [MHz] , GPU Temperature [°C] , Fan Speed (%) [%] , Fan Speed (RPM) [RPM] , Memory Used [MB] , GPU Load [%] , Memory Controller Load [%] , Video Engine Load [%] , Power Consumption [% TDP] , VDDC [V] ,
2012-09-11 15:21:01 , 1110.5 , 1502.3 , 47.0 , 41 , 1320 , 1298 , 44 , 17 , 0 , 65.7 , 1.1750 ,
44% was the higher value recorded.
So, there is a lot of optimization needed in the GPU side too.