system
A chat on subreddit /r/pcmasterrace
human
The cable connection from your laptop to your external monitor is limiting your refresh rate. If your laptop has a DisplayPort (DP) connection, use it. If you only have a HDMI, you may be limited to 120Hz.
gpt
HDMI can do 120Hz??

Edit: I guess somewhere in my setup I have an HDMI connection that can’t support it. Oh well. Main monitor is on DP running at 240Hz.