Fps - Hz and more - help!

[Caramidaru Andrei Bogdan]

By no means I am a tech guy, but I can build my own pc... My setup
I7 4970k
16G ddr3 1800mhz
2 x ssd Samsung pro evo(1 windows, 1 x steam)
1 x nvidia 980
27' Asus rog pg279q

PROBLEM :
ever since I got the Asus and put it to 144hz or 165hz I have huge spyke when playing raceroom, fps varies from 67-124 it's not stable.
So I think I need to put to 120hz, no?
Would a 980ti be any better?
With my setup what fps should I get in raceroom, rf2, dirt rally, assetto?
Didn't touch nvidia doctor or such, if anyone can give me some advice or settings for all sim would be greatly appreciated.
Thank you

 

[Emery]

Switching from 980 to 980ti would gain you a little, but probably not as much as you'd like.

Yes, 120 Hz is likely a better choice for monitor refresh with the fps you're seeing.

Raceroom (and other racing sims) has some setting adjustments to improve framerate. The tradeoff is reduced graphics fidelity. Only you can decide if those tradeoffs work for you, so you have to fiddle.

 

[Caramidaru Andrei Bogdan]

thank you, the problem is that i am home very rarely and when i am home i stay for a very short while, don't have time or patience to fiddle with those settings, and even more don't know what does what from FXXAA, Antianalsing and all that