When playing Battlefield 3, I get a framerate of about 20-30 FPS. When playing mutliplayer, maybe after 5 minutes or so the framerate will drop and stay at 4-8 FPS. When a new map is reloaded this resets.
I am wondering if there is any common graphics settings for this. I noticed that Catalyst reports my video memory as 4 GB "Hypermemory". Perhaps at some point RAM is being used for video memory? (The card is 1 GB), maybe disabling this will help?
Using GPU-Z, I noticed that when this happens by GPU load % drops from a steady 100% to 0-10%. So it is as if the graphics card stops being used. The dedicated and shared memory are not going to the capacity of the card, so I don't think hypermemory theory is right.