Hmmm ...
Not to sure on this.
I went MSI GTX 1080 EK X. Initial thoughts WOW I'm getting ~1975MHz in benches without OC (guessing down to nVidia Boost 3.0, card being within temps/powerlimit,etc). So last night for 1st time since owning I thought I'll game on it as I'd sorta finished with tweaks on newly built ThreadRipper setup.
I have clocked up on SWBF ~150hrs, had used my Fury X at 1440P with a 88FPS cap, so it stayed within FPS for FreeSync usage on MG279Q. Preset Ultra, even without using OC ROM on my Fury X I felt gameplay was smoother than GTX 1080. The 1080 was at same preset but no cap and V-Sync off.
So I thought let's cap FPS at say 120, use V-Sync, as I had seen FPS in the range of that and upto 144 using the GTX 1080. Upon entering the nVidia control panel I found no option to cap FPS :/ (missed AMD driver panel at this point). I thought OK I'll use RivaTuner to do a cap, then I thought try another game prior to spending time on these 'tweaks'.
So I fired up Lords of the fallen. I have completed this before, so again I'd say I have fair experience of how the Fury X behaves on this game with FreeSync. I used same in game settings, again V-Sync off. Again I felt the gameplay was better on Fury X with lower FPS but with FreeSync on.
Will be having another attack at 'tweaking' things tonight.
Next I'll explain how FreeSync helped on an older game in the past. Few months back I got Dead Space (yeah never played it on release, etc). When first used it was capped at 30 FPS IIRC, I thought WOT! So I disabled V-Sync and FPS went crazy in the 200+ range IIRC. So I capped it, I had this horrible line within the middle of the screen on movement. I tried game at various FPS caps, slightly lower than various refresh rates on 3 monitors (Eizo FG2421, Dell U2515H and Asus MG279Q). The way this line went was with using FreeSync on the MG279Q.
Currently I have some regret on just having parceled off my Fury X, which sold a day or so ago. If I do not manage to 'tweak' GTX 1080 to give a smooth gaming experience, as I recall on Fury X with FreeSync, then I think it will be VEGA time
.