Question PC stops working after a couple hours

[Blinvis]

Around a week ago I bought and installed some new ram. My computer booted up perfectly after installing it and still does but after around 2.5-3 hours it stops working. Like actions will be delayed and when I open task manager all of the stats for CPU, memory, disk, wifi and gpu are frozen and not updating. After a couple minutes of this happening no actions are registered and I have to restart the PC. So my question is, is my ram definitely dying or did I do something wrong? I pulled my old ram out and put the new sticks in the same places so I don't think I did anything wrong there.

 

[Lafong]

Do I understand correctly:

You bought the new RAM. You removed the old RAM. You then installed only the new RAM in the same slots where the old RAM had been.

Correct?

You can easily test the new RAM for defects.

You could also replace the new RAM with the old RAM and see if the freezing problem goes away.

It would help if you posted the complete specifications of both the old and the new RAM.

If you bought 2 new sticks, have you tried removing just one of them?