Friesians fps drop to 9 fps Underground (Tom Clancy's The Division)

I have a huge problem in DLTS Underground:
When we approach the end of the mission I have is the fps drops to 9 or occurs after killing the boss and go to loot ushiku open. Anyone have it already?

My system is a bit weak, but I normally go without friezes.
I5 3570k
24GB ram
GTX 660 MSI