First off, my system:

Intel i5-2400 @ 3.2 GHz
NVidia 560 TI
8 GB RAM
Windows 7 Home Premium

Even if putting the graphical fidelity of Divinity to an absolute minimum, my system isn't able to display the game in more than 45-50 DPS, with occassional dips down to 30 FPS and sometimes even 10 FPS. Other games (tested: Hearthstone, EVE Online, Kerbal Space Program, Civilization V) run solidly on 60 FPS with their respective graphical options at maximum. All games are played in a resolution of 1920x1200 pixels. I have no real explanation why especially Divinity is tanking, as other people with comparable setups have reported to me that their games are running fine for the most part.