CPU Usage while rendering A6 RC2

hello again,

i was wondering - is it normal behavior for cpu to spike up and down during rendering region? these small spikes happens all the time during this process, going from 100 to approx. 50-70 to 100.
preview below.. you can see it going down. i find it a bit amusing and dont recall it doing before

it could be due to adaptivity recalculation…

can you explain more? is it cpu related or software adjusted?
edit: oh, i see, its soft related. so i guess its fine..