Intel released the Skylake CPUs in mid-2015, as well as the Z170 chipset to go along with it. These features 4K video capability, ie. 3840x2160 resolution at 60 Hz.
Unfortunately, 4K is only available on motherboards that feature a DisplayPort connector. The majority of Z170 motherboards don't feature a DisplayPort connector.
Furthermore, the majority of 4K TVs don't feature a DisplayPort connector either. Instead, they feature HDMI 2.0 connectors. Skylake only supports HDMI 1.4 . What this means is that you will only be able to get 4K resolution with the built-in Skylake graphics at 30 Hz on your TV, rather than 60 Hz.
What this means is that if you want to drive your HDMI 2.0 4K TV at 60 Hz, you will need a a separate, discrete video card, such as one from with an AMD or nVidia chipset.
While an adapter from Club 3D exists to convert DisplayPort to HDMI 2.0, the reports of compatibility with various DisplayPort GPUs and HDMI 2.0 TVs are mixed. And in the context of a home theater, an HDMI 2.0 receiver may be in the mix as well, which would further complicate compatibility, and thus I would not recommend it.
The bottom line is - the Skylake and Z170 GPU is fairly useless in the context of a 4K home theater PC. If you are upgrading an existing HTPC, it would be best to just switch the discrete GPU to a new model, and skip Skylake altogether. If you are building one from scratch in 2016, you may still consider Skylake CPU and a Z170 motherboard, but you will most likely want to disable the built-in GPU and buy a separate one from AMD or nVidia. If you are on a budget, going for a previous generation of motherboard and CPUs may save you enough money to save for an HDMI 2.0 discrete GPU.
Unfortunately, 4K is only available on motherboards that feature a DisplayPort connector. The majority of Z170 motherboards don't feature a DisplayPort connector.
Furthermore, the majority of 4K TVs don't feature a DisplayPort connector either. Instead, they feature HDMI 2.0 connectors. Skylake only supports HDMI 1.4 . What this means is that you will only be able to get 4K resolution with the built-in Skylake graphics at 30 Hz on your TV, rather than 60 Hz.
What this means is that if you want to drive your HDMI 2.0 4K TV at 60 Hz, you will need a a separate, discrete video card, such as one from with an AMD or nVidia chipset.
While an adapter from Club 3D exists to convert DisplayPort to HDMI 2.0, the reports of compatibility with various DisplayPort GPUs and HDMI 2.0 TVs are mixed. And in the context of a home theater, an HDMI 2.0 receiver may be in the mix as well, which would further complicate compatibility, and thus I would not recommend it.
The bottom line is - the Skylake and Z170 GPU is fairly useless in the context of a 4K home theater PC. If you are upgrading an existing HTPC, it would be best to just switch the discrete GPU to a new model, and skip Skylake altogether. If you are building one from scratch in 2016, you may still consider Skylake CPU and a Z170 motherboard, but you will most likely want to disable the built-in GPU and buy a separate one from AMD or nVidia. If you are on a budget, going for a previous generation of motherboard and CPUs may save you enough money to save for an HDMI 2.0 discrete GPU.