You really must set Shadow quality to Low for a huge FPS boost. And eventually set "Other car details" to Medium.
There's really a problem with shadows and how taxing they are, and not even looking good.
FOR MEDIUM (GTX 780) OR LOW COMPUTER :
- deactivate shadows
- deactivate real mirrors
- deactivate post process
- deactivate environment reflection
- lower anti aliasing
- max AI = 6 and AI cars detail = low
Privilegate 3k or 4k resolution with AA off or level 1. If you have a full hd TV and a nvidia video card, use the DSR function with 3k or 4k with aa level 1 or aa off.
Use auto detail framerate : it is not a miracle solution but it works fine.
For the CPU, put the "real time algorythm" in the UI to X1.
With aproximely these settings I have 60 FPS 99% of the time with 4K (DSR), full track details, road details, texture details, anisotropic X16, best graphics settings in the nvidia driver (high quality textures etc.)
And I confirmed shadows is the worst setting for performance AND there is absolutely NO combination with good shadow graphics (even ultra + ultra).
Computer :
I5 2500K overclock = +15%
16GO ram
Gtx 780 gpu oveclock = +23%
***********pci express 16 2.0****************** due to bad motherboard.
I hope it will help some guys !