Question CPU upgrade suggestions ?

[Makatas]

My current PC specs:

• Motherboard: Gigabyte GA-Z97X-Gaming 3
• RAM: Kingston HyperX SAVAGE 4x8GB 2400Mhz
• CPU: Intel Core i5-4690K
• GPU: MSI GTX 1080 Ti Gaming X
• SSD: Kingston v300 240GB
• HDD: Western Digital WD20EURX 2TB
• PSU: Corsair RMi RM1000i 1000W
• CPU Cooler: Raijintek THEMIS Evo
• Case: Antec Nine Hundred Two

I feel like its time to finally upgrade my cpu, few months ago i freshly installed tiny10, but performance of my pc didnt improve much, things just seems so laggy, even playing league of legends sometimes drops below 100 fps(my monitor has 165 hz), so yeah im here to ask for budged upgrade to cpu suggestions, since im out of the loop for years now, and have no idea whats good whats bad whats new whats worth the price etc.

I'm aware that most likelly i need new motherboard for new cpu socket and ddr4 ram for the upgrade, but yeah im looking for something budget and would +/- match my gpu, or if price doesnt increase by much, maybe even something stronger that could be sufficient for maybe an gpu upgrade down the line, but last time i checked 1080ti is supposedly a very strong card, so if you do upgrade it, you go for the big expensive boys which also gonna require pricier cpu. If you can reccomend a cpu+motherboard+ram combo(if its as necesarry as i think it is) its even better. Btw i live in europe if that matters.

 

[triplex1]

i7-4790K the difference will be +10%
otherwise you build a new with mb-ram-cpu

 

[Makatas]

i7-4790K the difference will be +10%
otherwise you build a new with mb-ram-cpu

Yeah thats what i expected. Any suggestions for that?

 

[triplex1]

Yeah thats what i expected. Any suggestions for that?

if you can do it well
In another case, I would keep these and sell the rest, taking respectively AM4 and as cheap as possible, even used ones from someone who has changed platforms

• GPU: MSI GTX 1080 Ti Gaming X
• SSD: Kingston v300 240GB
• HDD: Western Digital WD20EURX 2TB
• PSU: Corsair RMi RM1000i 1000W

 

[Makatas]

if you can do it well
In another case, I would keep these and sell the rest, taking respectively AM4 and as cheap as possible, even used ones from someone who has changed platforms

• GPU: MSI GTX 1080 Ti Gaming X
• SSD: Kingston v300 240GB
• HDD: Western Digital WD20EURX 2TB
• PSU: Corsair RMi RM1000i 1000W

I didnt quite catch it, whats am4? And why would i need to change the case too? Im quite out of the loop of this kind of stuff, after getting this pc all those years ago with time passage i kinda lost interest in these kind of IT news.