Wanted to get into this game for so long but it runs like absolout garbage on my rig regardless of settings, i'm on a 680, i7 2600 @ 3.4ghz and 8GB RAM and when i get anywhere near more than 4 people in an area it goes to total crap.
Coincidently, someone asked me the same thing earlier today. So I will copy my reply here:
Yes, I do get poor performance when entering Agartha at times when it loads all the characters. Other than that, my performance fix is to drop the effects and lighting settings one notch to 3.8, from the advanced menu.
It's a very unique game indeed, best played with a game pad with dual analogue sticks of course!
I did come across the single-player co-op analogy used to describe the game's control mechanics and hence the requirement for dual analogue sticks. Another interesting reason to play the game, I thought.
Fortunately, and like most I imagine, I have a 360 gamepad that should fit the bill quite well.