That solved it. SMART sensors seemed to cause this issue. Thanks!
On another note: Why is there no VRAM Total sensor for my R390?
MSI Afterburner seems to have it.
As the title says, for my Rainmeter stuff I need the hwinfo thing running to get the sensor data, however running it in the background, causes my whole system to have these small 1 second micro-freezes every couple of seconds.
Any idea what's going on?