4k full option smooth again with no cpu latency and a new game called "smooth POE"

Hello!
Just started Ancestors yesterday and discover it was unplayable due to cpu latency. I tried every idea I found. Clean all shadowing folders and files and others mystical tricks related to fullscreen or servers and etc...
I was surprised when I tryed to play in 3840x2160 and this make the game more playable.
The last, not working reeally but maybe a little, was limiting frame rate to 30 fps and culling it at 60. Just after thinking around my cpu core limits.
But I remembered that long time ago, with a 750ti but not because of it, it was needed to inactive multithreading in game option, and decided to give it a try.

What a surprise! I can play with full graphic option, now with a 1060 6gb, in 4k 3840x2160 at 50 fps with absolutly no lag, I never saw the game so nice and smooth.

Not sure that this can help everyone with any configuration but I can't understand why I played this game so laggy for years because they say that unactivation of engine multithreading is (not recommended). I suppose that when I activated multithreading first time year's ago my system could handle this, but with low options and resolution, and when I upgraded my gfx I don't noticed any évolution, but now I know that multithreading is not well handled by POE on many system's.
Or maybe multithreading is more broken by the new patch.

My system is pretty old: I5-3570k, 1060 6Gb, ram 24Gb

I actually have a new game ands it's called POEnolag, nice and smooth than never, and it's WOAW! incredible!

Ok I need to try some bigger boosted map's, but I think this deserved a post.

Edit: The multithreading seems to not be deactivated, the 4 core of my proc are evenly used 40-60% depends of some context, 80% when loading and my 3D card is 80-90% used (30% before)
I suspect my cstate in bios is deactivated, because of some problem with it, my proc freq is x40 fixed (show 4.68mhz by w10 but probably an error)

I think my cstate is active in bios but global core frequencies factor is 40x (base throttle 3.40mhz), very close to cores limit, maybe more, I do that some day because of any reason. Maybe that can be linked to latency spikes.

Maybe my cstate don't work fully with this settings, but POE multithreading seems to not work properly too, all my core are functional even if multithreading is off.

This problem was allways here for me, I was forced to lower my graphics options on several precedent leagues to activate multithreading, maybe I even up my cores factor to 40x beacause of this. I had a 750ti years ago and it's the first time I can see the potential of my 1060gb that can handle all the graphical option at full.

This also worked for me. Tried a ton of things with the graphics and nothing worked but this did. No more crashes or studdering.

This makes no sense, yet I haven't crashed yet since going from 1440p to 4k and performance-wise it runs no worse. What's even happening with this game's performance anymore?