Help New 144hz Monitor only available in 100hz

[lloydcars18]

Hey Folks so just Bought this LG 34UC79G From here and must say its fantastic although when i go to change the Refresh rate 144hz isn't available.

Im currently using a GTX 650 TI and have the Supplied HDMI cable running through an Adapter into 1 of the DVI ports images below for reference please help

 

[lloydcars18]

Il try that when I get home and it's Not 1440p it's 2560x1080