I have noticed that the longer I play the game the worse FPS I get. For example today I've started with 100-120 FPS and in the last round after playing for about 90 minutes I had 40-60 FPS with stuttering (this might have been caused by server issues or I've just got an unoptimized map).
My other issue is if I play for 80-90 minutes in one sitting the game just hangs on the submitting results message as the last round ends and it doesn't put me back into the menu, Windows says that the program isn't responding and I have to close the game with task manager.
My config is the following: i5 4460, R9 290, 8GB RAM and game is on an SSD with Windows. I've checked RAM and VRAM usage in Afterburner, RAM usage was around 6,5GB and VRAM usage was around 3-3,5GB.