game lag [SOLVED]

[Sneaksie]

If it starts to lag after 5 minutes, it can be caused by CPU or GPU overheating and throttling down. You can install the MSI Afterburner tool, run it, the run the game and play it. As soon as the game starts to lag, Alt+Tab to desktop and look at MSI Afterburner graphs, check the GPU temperature and clock speed. If it does throttle down, you'll see that clock speed has been lowered.