Comment # 12 on bug 64801 from Alex Deucher

(In reply to comment #11)
> Created attachment 90044 [details]
> dmesg output
> 
> I too am seeing this. Particularly in games Euro Truck Simulator 2 and X3
> franchise. Graphical corruption is obvious. dmesg output attached.

You are seeing an out of system memory condition.  The driver is not able to
allocate enough memory to process the GPU's command buffer so the rendering
gets dropped which is why you are seeing corruption.