Originally Posted by vranac

Try to OC your 1090, that is a must!

I just can't belive that you get such poor results with that monster card.

I run the sim on 560 TI 1GB w/o any problems you mentioned,
with almost everything on max except building details on medium
and forest on low.
I have 2500k on 4.5 GHZ, but I'm shure that thuban on ~ 4 GHz
will perform very close.
Your 30% GPU usage points at problem, CPU can't fill GPU with data.

Also about shadows, I dont have problems with them at all,
but I saw some guys with ATI cards have it, maybe some driver settings,
or new driver will help.