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If you are looking for a large screen with 120fps support, then the Sony X850D is the best choice. It offers 1080p at 120Hz and excellent motion handling. All the latest display technologies, including HDR and HDMI 2.0 inputs, are supported as well. In addition of being a good gaming monitor, it performs well as a TV to enjoy movies and other content.
Specs
Pros
Pro Advantageous for gamers
PC gamers, or everyone thinking of using this TV as a PC monitor, will enjoy the multiple input resolutions and formats this TV supports, including HDR support. But the biggest advantage for gamers is the 120 Hz input signal support for this screen at 1080p resolution, since it's a very rare feature. It also supports chroma 4:4:4 sampling rate, meaning that there will be no visible artifacts or loss of details when editing documents or pictures.
Pro Low input lag in almost every condition
The input lag is low if you use a FullHD resolution. On top of that, if it is a 120Hz signal, the gaming experience will be smooth and responsive and should please even the most demanding gamers. However, if the input resolution goes up to 4K, the input lag rises significantly and will start to become noticeable in fast paced action games.