Upgrade CPU?

[Blubbis]

Hey! I was wondering if I should upgrade my CPU. Or maybe something else needs an upgrade?
I play games like Modern Warfare, PUBG and Apex and my PC is struggling to get FPS over 100. Also my CPU is running at constant 100% when gaming. 

 

This is my PC specs:

Intel Core i5-6600K

ASUS Z170-PRO, Socket-1151

EVGA GeForce GTX 1080 SC

16 GB RAM

 

So can a i7 9700K or i9 9900K increase my FPS? Or do I need a better GPU?

[Uptivuptiz]

It's clear that the CPU is a bottleneck when gaming.

Since you need to buy a new motherboard to upgrade the CPU I recommend that you go with a Ryzen 3600X.

[191x7]

You could try with an used i7 6700(K) or 7700(K), that would help a bit.

Or you could go with 6+ cores, like a Ryzen 5/7/9 or modern i5/i7/i9.

[Uptivuptiz]

Just now, 191x7 said:

You could try with an used i7 6700(K) or 7700(K), that would help a bit.

 

In my old system I had a 6700K (not OCed) and i was still hitting the bottleneck. 6 cores is recommended.

[Akira Shimazu]

21 minutes ago, Uptivuptiz said:

In my old system I had a 6700K (not OCed) and i was still hitting the bottleneck. 6 cores is recommended.

its 1080. always expect 6 core with gpu above 1060 or RX 580.

 

3600 its best bang for budget. but if you want to go intel then something like 9400F probably done well. i dunno

[Blubbis]

Thank you guys for your replies! 

I was thinking a 7900K since the bottleneck calculator says only 4 % bottleneck. Do you think it will make a difference?