Can't prove it, but how the game "schedules" effects is F%^ed up... for one shadow complexity is NOT hardware accelerated and the more you turn it up the more disk swapping seems to occur, with it turned all the way up my 4690k@4.5ghz with 16gb ram and a 4gb-nv-760 galaxy card stuttered like a MOFO on belasvis when trees came overhead.
I though" .. "that's F^&*ing weird" .. WZ fine, FP fine, Belsavis = lag fest at 40fps ?? .... hmmm
started to play with the graphics settings and clicked "ultra" ... I was custom before by setting everything to max. noted a dramatic increase in response and less stutter. and then it hit me,... the cpu temp dropped from 55c to 35c like magic. now it was on...
toggled all the s%%t in the graphics panel until I hit the shadow complexity slider... bingo. Set it all the way right and BAM 55c and micro stuttering under trees in belsavis.. set it all the way left, 35c... no stuttering, 75.5fps at all times (refresh rate limit of monitor)
my opinion, and conclusion .. shadows are not hardware accelerated to have a 20 Celsius impact on the cpu.. awesome. and -0- Celsius or load on the gpu.