When starting the game I get reasonable FPS (between 20-25) certainly not great but ok for a Beta. But then after certain amount of playtime (~30 minutes) the FPS drop dramatically to below 5 FPS. This always happens and only restarting the game solves the problem (tried changing zones, going back to the character screen, changing graphics settings back and forth etc…).
It can happen that for short periods the FPS go back to normal but this is always temporarily the game from then onwards runs at very low FPS.
I checked CPU load, memory usage etc… but all seem to be ok (although 7GB for the game is quite a lot of memory to use, but I have 16GB so this still fits).