Trying to figure out what upgrade to make?

NeonSurge

Honorable
Jul 1, 2014
6
0
10,510
Hello friends. I am going to make an essential upgrade to my PC in a few days and I have a budget of about 400$. Here are my specs.

Specs:
OS: Windows 10
Motherboard: Maximus VII Hero
Video card: Nvidia gtx 1070
CPU: Intel i5 4690k quad core
Power supply: cx 600
8 gigs of ram Dual monitor set up
1 TB Harddrive and 256 GB SSD.

It seems like from what I have heard that if I want my computer to run better and I have money for one major upgrade I figured I should upgrade my CPU, or is there something else I should upgrade first? Any thoughts on this? And also what is a good modern CPU for gaming? I heard good things about the Intel i7 8700k and 7700k but I learned they are not compatible with my motherboard. Should I just upgrade my motherboard first and then get a good CPU? And if so what motherboard?

This website I am about to link gives me all the compatible CPUS with my motherboard but theres so many options and I want to choose a good one for gaming that I don't know where to start. If anybody can give me ANY advice I would appreciate you so much!

https://www.asus.com/us/Motherboards/MAXIMUS_VII_HERO/HelpDesk_CPU/

Also, does anybody know of any other sites or people I could talk to see what parts I should upgrade in my computer and what exact parts I should buy? You guys are my only hope and I don't really know who else to ask. Any insight or advice from any of you wonderful people would be much appreciated. Thanks :)