while checking the traffic statistics of the router, i noticed a HUGE amount of outgoing traffic. Turns out there is process with title "AMD User Experience Master" (located in "C:\Program Files\AMD\Performance Profile Client\AUEPMaster.exe") which is responsible for this. This process seems to be part of the default graphic driver installation. It contacts in regular time intervals some AWS-service causing an averaged uplink consumption of around 0.1 MB/s. This corresponds to 8.6 GB per day per computer. Why is it necessary to send that much data? Apparently opting out of some program in the settings stops this, but generating that much traffic in the first place is irresponsible.
In addition to the above is is also worth noting, that the bandwidth consumption is not continuous but "pulsed" with much higher peak bandwidths than the average rate indicates. So this may cause noticeable latency spikes and similar issues.