The 3840 x 2160 ‘4K’ UHD resolution requires considerable graphical grunt to run on demanding applications, such as some games. Users may therefore consider running a lower resolution such as 1920 x 1080 – and indeed if they are connected to a modern games console, this sort of lower resolution will be all they can use. If you connect the monitor up to a PC via DP 1.2, the interpolation (scaling) process is handled exclusively by the GPU. There is significant softening to the image compared to running the resolution natively, whether you select 1920 x 1080 (Full HD), 2560 x 1440 (WQHD) or something else. Whilst gaming, it looks as if you’re looking at the game world through a soft-focus lens.
If you’re connected using HDMI, either to a PC or games console, the monitor does have scaling features and will be able to use its own interpolation processing to handle non-native resolutions. As a PC user you should ensure that the monitor rather than GPU is handling this. If you’re using an Nvidia GPU (more likely with this monitor) you should open the Nvidia Control Panel and navigate to ‘Display – Adjust desktop size and position’. Ensure ‘No Scaling’ is selected and ‘Perform scaling on:’ is set to ‘Display’ as shown below. AMD GPU users shouldn’t need to change anything as the drivers are set up so that the monitor will handle interpolation, where possible, in games.