Chotch, perhaps don't expect a reply till the 4th, it is holidays. So I doubt not much could be done about it until they open up again. So I'm playing on DX11 atm, I suggest you should as well until this issue is resolved.

I have this with a 980SC as well. Changing MSAA to 2x (or less) and using Temporal AA helps. This, for me, was new with the latest version of the Alpha and/or latest Win10 updates.

Welcome to your DX 11 Card

I was thinking perhaps turn down the textures, and see how it goes. Also turn of MSAA. I think this will work.

Their GPU's Can't process Async. well. It will bottleneck. You can not compute multiple shaders at once if you do not have the ability to do so. So, there is no point putting on MSAA with a NVIDIA GPU> 

I will send some more photo's to show you what A NVDIA does under DX12 conditions - give me a few days, am busy with work, and the other ones were taken down - so I need to repost them

Mind you this is one a 2 core processor I3, so the FPS is low. But you can see how the graphics card acts - if you note the shadow quality is High. So, there is no need to have an FPS Cap. The Stable FPS is there. Furthermore, you can see the CPU Stability.

DX12 Async :

http://imgur.com/GBgcWBc

But as you can see the FPS is very stable with an AMD, and also the efficiency of the CPU

Can you post your Benchmark. On the steam forum.

If you note this is how an AMD acts in DX11

https://imgur.com/grzSBqO

As you can see the FPS is very unstable, and also the GPU, CPU

Should I buy a NVIDIA for DX12 - No. Unless it can process Aysnc. Currently their GPU's do not. Just because a NVIDIA GPU has a fast GPU - some of the more expensive GPU's does not mean it can do this >:

http://www.amd.com/PublishingImages/graphics/tables/570px/directx12-gpu-performance.jpg

Related article

http://www.amd.com/en-us/innovations/software-technologies/directx12