It perhaps could be the motherboard, but it still sounds a little unlikely from my perspective.
At this point I would guess it is related to some sort of service, like every 10 minutes some program goes out and looks for an update on the internet or something like that.
It would be kinda hard to narrow that down, you would have to search for services and go through manually shutting off stuff that lists itself as started. Also you would have to close out of all the other programs you have open and anything you have loaded in the task bar that isn't necessary for Windows to operate.
You would know if you stopped the wrong service because it would cause large instability issues.
Obviously stuff like the firewall service would be good to leave on.
Does this happen in every game or just one or a few games?