High fps is smooth but 50-60fps is choppy

[Sinlol]

So I have had this issue with World of Warcraft where high fps is normal to the eye.
but when i get in a raid and alot of stuff is going on, im in the 50-60fps range and it almost looks like its 15 fps. really bad stuttering
whats going on here? this build really shouldnt be struggling right?

msi 1080 duke GPU
i7-8700k no overclock
240 hz alienware 25' monitor. with GSYNC
z370-a prime motherboard
corsair vengeane LPX 3000

 

[logainofhades]

Raids are always bad for performance. If you are full on ultra, drop shadows to low, and view distance to 7.