Strange performance issue

[Gamerkought]

Perhaps some background app running? I know that some antivirus progs or windows update can suddenly start and steal resources.

It might also be a card overheating program, and if so you need to check temperatures when playing or just clean it (can be a lot of dust in fan).

No, it's the same problem for me too. All I have to do is restart the game and everything works fine. I don't think it's another program interfering.