Huge framerate drop after an hour of playing

[JulieEaster]

Hello there,

My current setup is Core i5 and HD7870 with 8GBs of RAM, i play at 1080p windowed and borderless most of the time and i'm hooked up on a second small 17" monitor as well. My drivers are constantly updated.

With that out of the way, here comes my problem.

Since the launch of patch 3.1, I'm having huge frame rate drops after i've played for an hour. Normally i'd have stable 60fps no matter where i go, even if at huge areas like Hinterlands or Asys Lla, i'd still get at least 50fps. But after an hour of playing, it'll drop to about 30-40fps and the games feel laggy and slow. The problem would only gets worse and sometimes down to 20FPS when i'm at Azys Lla. I don't think its a memory leak problem as my RAM consumption is always about 400-500MB. The problem would go away for another hour if I restart my PC.

I wonder if anyone is having this problem and hopefully we can work out a solution, thank you.