Adjust for less host CPU consumption

Hi

Ok since i have the POCO i ran it on Protools ( mainly TC master X3 ) for mastering with all Tc Control panel settings on default . I had a few issues dropouts etc. but i could work so i leave it that way . The thing is that about a few days ago i decided to tweak the Tc CP a little and changed the CPU setting to :

Adjust for less host CPU consumption .   

And WOW not only runs better now SOUNDS better ...how is this posible ? Before i ever hear a litter harsh top end and after it sounds so smooth and transparent !

Thanks for any input !