OSX VST/AU cpu consumption when Off?

[aex1]

Maybe this has been covered before but i couldnt find an appropriate thread so far. so here it goes ..

.. in an empty liveset, with transport not running, i insert like 5 random VST FXs or Instruments and my cpu goes from 10 to 30. when i turn them all off but leave them where they are, cpu goes back to 10. sounds ok. hitting play doesnt change the situation.

if instead i pick any 5 AUs, see my meter go to 30 and then turm them off, the meter stays around 15 or more, instead of dropping back to 10. when looking at particular plugs, blockfish or apple Hipass use 1% when being Off, musolomo takes 4%, morefeedbackmachine 2%. Automat and Podolski, both synths, seem to eat nothing when Off.

hm, i dont think im the 1st person to wonder about this, so maybe someone can explain this to me? at first i was vaguely thinking live needs some additional juice even when plugs are turned off cause it must respond immediatly when an effect happens to be switched on, more immedietaly than other non-live-performance hosts have to. but obviously this would apply to VST format plugs as well, and yet those dont eat nuttin when theyre off. so it sounds like an AU quirk, or Live+AU quirk. i dont have other hosts to compare.

thanks for any info.