Check if the graphics card supports the spec by referring to the homepage of the graphics card maker.
Try this
Check if the model in use is 27GK750F.
Check if the monitor terminal such as HDMI 2.0, DisplayPort 1.2 and so on are existing in the graphic card and check if
the graphics card’s vertical frequency output spec for each terminal meets the 240Hz requirement.
Check if the graphics card supports the spec by referring to the homepage of the graphics card maker.
In case of HDMI connection
1. Connect it to a graphics card that supports HDMI 2.0.
※ Some older graphics cards do not support HDMI 2.0,but you can select HDMI 2.0 resolution in the control panel of window.
2. Set Monitor OSD → General → HDMI Compatibility Mode → Off.
※ When HDMI Compatibility Mode is on, 1920 x 1080 @ 144/240Hz resolution is not supported.
3. In the Windows display property menu and the graphics card control panel, set the vertical frequency of 240Hz.
In case of DisplayPort connection
1. nitor OSD → General → DisplayPort 1.2 → Enables.
2. In the Windows display property menu and the graphics card control panel, set the vertical frequency of 240Hz.
This guide was created for all models, so the images or content may be different from your product.