How to get full screen and 4k resolution

[Deadbone]

Hey guys, i recently purchased Alienware AW3418DW to hook it up with my Xbox X which i did using high speed HDMI cable but no luck in getting 4k resolution nor a full screen. It's just rectangular small screen and black on both side.

Please hhhhheeeeelllllppppp!!!!

 

[Couriant]

Try the onboard diagnostics. Also make sure your Xbox is outputting the correct resolution etc.

Having said that, I believe the HDMI port is version 1.4, which supposedly is not good for gaming consoles. I would recommend contacting the vendor for clarification.