acer predator xb271hu question

[SimonNo1]

I own the following monitor acer predator xb271hu

When games drop below 100fps to my eyes it feels strange, kind of like a choppy feeling is this normal as the monitor is 165hz?

PC Specs

I7-7700K @4.6
32 GB DDR4 3200
GTX 1080ti
Z170A tomahawk MB

I use to think 60fps was fine but now it looks aweful to my eyes

 

[SimonNo1]

V-sync is not on only G-Sync is on.