do triggers slow down my pc?

[Hasi]

I ask myself sometimes if some triggers slow down the pc system,
especially such, which run if some window is open/visible.

is there a request for example every 0.5 seconds, if any window is visible, or how does qm get aware about such changes that initiates the trigger?

although qm runs quiet in the background...

[Gintaras]

Should not slow down. Uses various hooks. OS notifies about events. QM does not enumerate windows etc.

[Hasi]