Playing directx-10 on a directx-11, & unparked core question

In a never ending effort to sew a silk purse with a sow's ear, I'm looking for any possible way to eek out extra FPS, and get the American Roads mod to open up. All with a sub-par AMD FX-8120.

So I just uninstalled the latest version from Steam and reinstalled the back-issue v.14 with the DirectX10, hoping that a lower version number automatically means higher FPS. Question is, if my computer (Windows 7/64) and graphics card (AMD Radeon 7870) are DirectX11, are they backwards compatible and can they run DX10?

Also, I was reading around online and found this info about unparking CPU cores, and how it will make my tired old AMD run a little faster. Now I know nothing about this sort of stuff, but thought if some people have had favorable results, figured I'd give it a try.

Well upon firing up the game, things have gotten way worse. 15-30 fps tops in small grid, 12-15 tops in ECA, and WCA wouldn't even open. "Not responding" said the application tab in Task Manager.

So where did I go wrong? Was it the assumption that the DX10 version would run with a DX11 setup? Or was it the assumption that unparking all the cores would make the game run better?

Either way, I guess I'm going to undo one and/or both and see where I see the improvement first.

 

The only next practical step is to isolate the two things you did and find out what's the culprit. Check out this thread, even though your cpu may not fall under this:
https://linustechtips.com/main/topic/423121-unparking-cpus-is-it-worth-it/

 

Thank you for sharing this. I’m in the process of isolating these two right now.

 

Unless you're somehow forcing your card to run in a DX10 mode, you're still using DX11. Newer cards/drivers cease to optimize for previous DX versions. You aren't going to get better performance out of DX10 or DX9 even if you forced it to run in those modes.

 

Ok thanks. That’s what I wanted to know regarding DX’s. I’ve uninstalled the v0.14... & am in the process of reinstalling the v0.15.0.6
as I type.
Now to maybe test the unparked cores with the v15, as that’s the one combination I had managed to omit. (I had tested unparked with v14). But from what others have said, I really doubt I’ll notice that much improvement.