Thanks for the posts guys
I will try to update my sound card drivers, run off onboard, etc. Googling around it seems several people have had issues with audio in various Ubisoft games.
I've also since read that AC3 does not scale well with multiple cores, I suppose I was just shocked at how much of a hit TXAA saddled me with. But I suppose that's the trade off for multimonitor
Also, 5890x1080 was bezel corrected, sorry for the confusion!