Just as an experiment, I dropped my resolution to 1600x900 to see if it would iron things out.
I still get hard dips from 60fps into the mid-40s every 10 seconds or so, and massive hitches around structures (houses, buildings) with relatively sustained low-50's, where the controls become unbearably sluggish and unresponsive -- with and without vsync enabled.
Can't get 30fps to feel smooth with or without vsync enabled as well -- to me, it feels as if it definitively lacks the controller response of the moments of smooth 60fps gameplay I can get or the XB1 version which is also locked to 30fps. I don't have tools to measure frame pacing right now but I definitely feel there's a lack of controller response in those instances too, despite the 30fps counter never budging. I haven't tried to adjust my monitor to 30Hz
For background, game defaulted to "High" preset with the dynamic setting on when I first booted it up.
Again, this is playing on my gaming laptop: MSI GS63VR Stealth Pro (068 configuration)
- i7-6700HQ 2.6GHz
- GTX 1060 6GB
- 16GB DDR4 2400MHz
- 512GB SSD (PCI-E m.2 slot)
Feel like my spec is confirming the theory that the game relies on high clock speeds across the board (CPU, GPU, RAM) in its current state. Bit of a shame. I'm not super cool with the idea of rebooting into my BIOS to toggle hyperthreading on/off when I wanna play Forza, so I'm just going to stick to XB1 for now and hope they can sort it out for lower clocked machines, if at all possible. Sad no 60fps Horizon 3 for now.