Want to upgrade motherboard/cpu to get the best use of my 1080ti

[mesterjester]

I built this PC five years ago, the one listed in SophieBeth100's first reply in this thread:

http://www.tomshardware.com/forum/id-1736449/gaming-build-advice-1400ish-budget.html

Last year, feeling the age of the video card, I upgraded to a 1080ti. Now, based on some quick research, I believe I'm starting to be badly CPU bound in newer games (I get 43 fps in "AC: Odyssey" on Very High settings regardless of the resolution I pick.).

Can someone suggest a good motherboard/CPU combination (and I'm assuming I'll need new RAM as well) I can upgrade to that would let me keep the majority of the other components, and knowing that I have the 1080ti already? I'm looking to upgrade the display to a 4k/hdr TV later this fall if that matters for anything.

Price-wise, I don't want to go "ultimate, top-of-the-line" but I don't want "barely-an-upgrade" either. Getting another 3 - 5 years out of it would be nice though.

Thanks!

 

[norcalsc]

I5 8400
Z370 will vary based on form factor

 

[mesterjester]

I5 8400
Z370 will vary based on form factor

Hey, would you be able to give me a little more detail in this answer? I've supplied more information below.

The 1080ti I have is the Gigabyte AORUS GeForce GTX 1080 Ti. I'm likely going to be upgrading to a Vizio P65 TV later this fall. I don't overclock and am mostly interested in the 4K/HDR aspect of the end result, not super high framerates. This TV does 4k@60hz and 1080@120hz, but I'll be focusing on the 4k@60 side of things. I like the higher res/detail rather than the higher framerates.

Could you possibly suggest a specific cpu/motherboard/ram set that might come in at under $500 that meets these goals, if that's possible? And ideally, one that would fit in my existing case?

Thanks!

 

[norcalsc]

this is a good setup for 550$ i5 8600k z370 board 16gb gskill check it out
https://www.newegg.com/Product/ComboBundleDetails.aspx?ItemList=Combo.3792698