Marcin, it seems to me that it's a processor, try to insert a different one for the test:] and I would advise you to use something less memory-intensive, for example, use an emulator game or something like that.
To the author of the topic, I think it is the fault of the power supply, unless ... How much time do you have this computer? Capacitors sometimes get damaged from the inside, which is imperceptible, measure the voltage. Are both ram bones the same type ?? Update the bios.
To the author of the topic, I think it is the fault of the power supply, unless ... How much time do you have this computer? Capacitors sometimes get damaged from the inside, which is imperceptible, measure the voltage. Are both ram bones the same type ?? Update the bios.