Help me get my gaming PC 4K capable.  I built the PC last fall with the intent of making it fully 4K capable this spring, but I'm not sure how to go about doing that now.

First, the specs:

MSI B50 Gaming M3 motherboard
Intel skylake i3-6100
EVGA GeForce GTX 1060 GPU
8 GB DDR4 RAM
240 GB SSD
1 TB HDD
internal DVD drive
750W Power Supply


I want to be able to play 4K video from Netflix, Amazon Prime, YouTube, and UHD Blu-ray.  YouTube plays in 4K on the system as it stands.  I haven't tried Netflix or Prime yet but they should as well, because Nvidia's current drivers for the GPU allow DRM protected 4K playback.

That leaves UHD Blu-rays.  The only UHD Blu-ray drive on the market right now is the Pioneer BDR-211UBK.  The drive requires the video to be processed through the CPU, which means I need to upgrade to a Kaby Lake CPU.  Also, the current motherboard's output is HDMI 1.4, which does not support 4K.  The video card has HDMI 2.0 outputs.

I know I need the Blu-ray drive itself and a Kaby Lake CPU in order to play UHD blu-rays.  The question is, if I upgrade the CPU and install the drive, will the video output go through the GPU or the motherboard?  I currently have my monitor connected to the HDMI port on the GPU.  If it will only output from the motherboard, then I'll need to upgrade that too in order to get HDMI 2.0 outputs.


TL;DR

If a UHD Blu-ray drive forces the computer to process video on the CPU, does that force the video output to come from the motherboard, or can it still come out the GPU output?

Video will output via the hdmi port on your video card. So that should be fine.  You will also need software to play the UHD movies. 

Cool, that saves me from having to change the motherboard.

What software is recommended for UHD Blu-rays?

I believe the Latest version of PowerDVD supports UHD playback.  
Looks like you need the Ultra version for UHD playback.

https://www.cyberlink.com/products/powerdvd-ultra/compare-versions_en_US.html