Well it does make my PC go slow when it updates, whether this is a motherboard issue I dont know as Ive noticed peculiar performance issues with hard drive usage. Im going to change the motherboard soon anyway so I hope those issues are fixed.
But I can deal with the 5-10 seconds of slowness, but what I cant deal with and shouldnt have to really, is the delay it invokes when it tries to update immediately on booting into windows.
Its like I login to windows and the first thing that happens after avast loads (and it does that pretty quickly) is that it will try to update, resulting in everything else loading very slowly indeed. There should be an option to stop it doing this but so far just turning off automatic updates completely has stopped it. I cant really load any programs until its stopped updating.