Well I will tell you my specs and this is weird, I would be able to run the game in ultra och very high atleast? tried everything at that point with no success...
It lags alot and some seconds its very smooth.

so:

Windows 7 Ultimate 64
GTX 780
i7-4790K 4.00GHz
16GB RAM
Samsung SSD 840 EVO 250GB
2TB black harddrive

So my question is, what settings can I have? and exacly what would I have in settings?