After playing 30 hours with perfectly normal fps on ultra settings last week I have now started to get HUGE fps drops.

Makes the game often completely unplayable as the fps is literally 1.

Usually happens when looking in certain directions, and when looking away goes back to normal until you look back at the "problem zone".

Light sources (including the sun) seem to often cause a problem.

Looking at your feet usually solves it until you look back up again.

There are also seemingly random freezes but those go away in a few seconds whereas the directional freeze doesn't go away until restart.

This happens in ALL locations, including all the ones that used to be fine!

Changing settings does nothing, same problem whether I have every setting at minimum or maximum.

Can this be caused by a patch or how else could it start only now after 30 hours with no problems?