Kilobit81

I use Gskill Ripjaw V DDR4 3600 17-18-18-38 @ 3600 MHz Quad Channel on my Threadripper 1950X

The i7 8700k will give you higher fps. The Ryzen 5 2600k is cheaper but slower than the i7 8700k in single core performance but faster in multithreaded performance. The FX is the slowest overall but it will give you smoother gameplay than both. I have the Threadripper 1950X and the FX 9590 both are great for gaming but I do not experience any screen tearing on the FX but I do sometimes on the Threadripper but I do not experience any microstutter on either but I do on my i7 3770K.

DX12 is actually far superior if the game is developed on Radeon hardware. If the developers are using Nvidia hardware they are forced to implement Nvidia Proprietary instructions which are not truly optimized for DX12. To give you an example Radeons use True Asynchronous Compute which is a feature in DX12. Nvidia has a proprietary simulated asynch compute firmware implemented which may increase 5-10 fps on Nvidia hardware but not benefit AMD hardware. True Asynchronous Compute utilizes more of the GPU's hardware and increases performance anywhere from 15-20fps in most games. A couple of good examples are Forza 7 and Wolfenstein 2 The New Colossus where Microsoft DX12's True Asynchronous Compute is used. When Ashes of the Singularity Launched it originally used True Asynchronous Compute and the Radeon's blew passed the Geforce cards but Nvidia had told them their hardware did not have support for that instruction and asked them to implement Nvidia's proprietary Simulated Asynch Compute instruction instead. When Stardock and Oxide Games were persuaded to do so the Radeon's performance dropped dramatically and the Geforce's performance increased significantly.

The Vega 64 is faster in Microsoft titles because Microsoft implements true Asynchronous Compute in their DX12 titles. Nvidia requested developers to not implement True Asynchronous Compute in their DX12 titles because it would give AMD a large advantage. They did however request developers to use their proprietary Asynch Compute instructions because Nvidia does not have support for True Asynchronous Compute. Nvidia uses a simulated Asynch Compute implemented in their BIOS firmware which requires their instructions. If True Asynchronous Compute was implemented in all DX 12 titles the Vega 64 would destroy the Geforce 1080ti in every benchmark.

The reason Forza 7 and other XBOX exclusives run better on AMD is because Microsoft uses DX12's True Asynch Compute. Nvidia implemented simulated Asynch Compute in their firmware. Most game developers were "asked" by Nvidia to not utilize True Asynch Compute instructions because their cards do not have True Asynch Compute Hardware. If all developers used True Asynch Compute AMD would have a significant performance advantage over Nvidia across all DX12 titles.

There is an AMD official updated R9 Fury X Bios that was released in April 2016 which improves overclocking stability. I keep mine at 1170/500 through Sapphire Trixx. I can overclock the HBM but it reduces performance. It is 99.7% stable in Fire Strike Ultra stress test which is more stable than the stock clocks which comes in @ 96.7% stable.