Latest 4K 144 Hz Monitors use Blurry Chroma Subsampling
Just a while ago the first 4K 144 Hz monitors became available with the ASUS PG27UQ and Acer X27. These $2,000 monitors no longer force gamers to pick between high-refresh rate or high resolution, since they support 3840x2160 and refresh rates up to 144 Hz. However, reviews of early-adopters report a noticeable degradation in image quality when these monitors are running at 144 Hz. Surprisingly refresh rates of 120 Hz and below look perfectly sharp.The underlying reason for that is the DisplayPort 1.4 interface, which provides 26 Gbits/s of bandwidth, just enough for full 4K at 120 Hz. So monitor vendors had to get creative to achieve the magic 144 Hz that they were shooting for. The solution comes from old television technology in form of chroma subsampling (YCbCr), which, in the case of these monitors, transmits the grayscale portion of the image at full resolution (3840x2160) and the color information at half the horizontal resolution (1920x2160).