To be honest, it could be the Phenom - its an old bird nowadays.
However I also used to get these problems when I OC'd my GPU with an unstable clock - it didn't show artifacts, just FPS stuttering.
Do you have a spare PSU to test? The voltage on the 12v rail could be fluctuating.
Thank you for your replies! I really appreciate it!
Already? I mean, could a bit newer Phenom II X4 960 do the trick here? (my Phenom is actually a 940)
I am using HWMonitor and the processor starts off at 60ºC, there's definitely something wrong here...
I am going to leave the trying with another PSU thing on hold I guess...
I captured the video with a camera, so, yeah unfortunately not.
That would be an easy and a better diagnostic at this point.
I am going to attach an image of both the voltage and the temperature at startup.
Probably something wrong there.
My case has a very very high airflow it's a Cooler Master with a 40cm diameter fan; I bought it because of a malfunction of my previous GPU that reached 105ºC easily.