I was playing it fine like 15 hours, then I left the game afk for 20 mins and it started to lag really bad. I have rebooted, and fps got back to 60, and after 10 mins ingame it turned back 30. Again and again.

Sounds like this:

• ██"Low frame rate with hardware exceeding recommended / starts at 60fps then drops to 20fps until restart" http://www.gamesas.com/topic/1544320-incredibly-poor-performance-unoptimised/ http://www.gamesas.com/topic/1544248-bug-report-index-pc/#entry24473184 http://www.gamesas.com/topic/1544248-bug-report-index-pc/page-11#entry24518898 http://www.gamesas.com/topic/1544248-bug-report-index-pc/page-12#entry24523674

It has been reported and logged in: http://www.gamesas.com/topic/1544248-bug-report-index-pc/

If its not the same please report it in the thread so it can be cataloged.

That's it.