Running minecraft isn't very smooth at 120fps?

[astromashy]

So I recently built my pc: specs:
Intel core i5 4670K
Asus-Z87K
Nvidia gtx 760
8GB crucial ram
samsung evo 840
wd red 1tb
corsair cx500

Anyway on minecraft I'm getting 120 fps but the game seems quite stuttery and not very smooth some of the time? I have installed all the drivers but the game just seems to lag quite a lot, in terms of fluidity. I'm not talking about connection as it's the same on single player. Any ideas?

 

[RazerZ]

Did you try enabling V-sync?

 

[astromashy]

I disabled it because sometimes my fps was going down to 40 and it was pretty laggy. I turned it off and I have my max framerate at 120fps and that's what it says I get fps wise...