PCPartPicker part list / Price breakdown by merchant
CPU: Intel - Pentium G4560 3.5GHz Dual-Core Processor ($68.99 @ SuperBiiz)
Motherboard: MSI - H110M Gaming Micro ATX LGA1151 Motherboard ($41.98 @ Newegg)
Memory: G.Skill - Ripjaws 4 series 8GB (2 x 4GB) DDR4-2400 Memory ($59.92 @ Amazon)
Storage: Western Digital - Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($48.44 @ OutletPC)
Video Card: EVGA - GeForce GTX 1060 6GB 6GB SC GAMING Video Card ($226.99 @ Newegg)
Case: Xion - XON-310_BK MicroATX Mid Tower Case ($23.98 @ Newegg)
Power Supply: EVGA - 430W 80+ Certified ATX Power Supply ($21.98 @ Newegg)
Keyboard: Verbatim - 99201 Wired Standard Keyboard ($6.10 @ Amazon)
Mouse: V7 - M30P20-7N Wired Optical Mouse ($3.99 @ Amazon)
Total: $502.37
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-06-16 20:16 EDT-0400
You can get W10 for free legally; https://www.howtogeek.com/272201/all-the-ways-you-can-still-get-windows-10-for-free/
The XBX has a very mediocre Jaguar based CPU, basically the same as the one from the original XBONE but clocked higher. Even with the seperate DX12 unit, it's really not hard to beat and the G4560 will easily do the job. Yes, despite being a hyperthreaded dual core CPU, it won't even bottleneck the GTX 1060. Using the FX series is completely arbitrary in this case just because the XBX has eight cores.
The GPU is basically an RX 580, which the 1060 beats in most instances, most often not by much though.
The XBX has 3GB of RAM reserved for the OS, which is about the same W10 takes up on average during gameplay. This makes sense considering the OS on XBX is based off W10 IIRC. That leaves 6GB of DDR4 for CPU bound tasks. The XBX has 9GB left for both GPU and CPU tasks. The balance depends on the game, but it most certainly won't have 6GB constantly reserved for the GPU. In turn, the build has more and better organized RAM, not to mention a bit faster. GDDR5 is based off DDR3 and doesn't perform much better than it when used for CPU bound tasks, so even with the faster tick rate it's the same or slower than the DDR4 RAM on the PC For CPU bound tasks.
As for the magic "console optimization", first party titles might see a notable difference, but in most instances third party developers won't bother to take the effort to make a notable difference that will push performance to the likes of the GTX 1070 nor is that even feasible most of the time. Console optimization can only take you so far, and that isn't very far at all.
It doesn't include the Blu - Ray drive, which while most gamers don't need could probably be covered by the cost of XBOX LIVE GOLD for one year. The cheapest on PCPartPicker is $43, and a case that has an optical drive slot costs $25 (compared to the one in the build above for $23), which adds up to $547 compared to $502 (under $60 extra).
This is what's feasible now, but by the time XBX releases these builds will most likely get even more competitive for the same price as new parts come out and prices start dropping.
Also, here's a well written Reddit post on the XBX; https://www.reddit.com/r/pcmasterrace/comments/6h96rt/yes_the_xbox_one_x_is_pretty_good_but_here_are/
