1440p 240hz

Recently bought the Alienware AW2721D monitor and unfortunately i have been having problems configuring it so far. I got it working now at 2560x1440 resolution, 8bpc colors but i just cannot get the refresh rate more than 144hz. Every time i try to choose 200 or 240, the display switches off...

I'm considering 1440p @240hz, but i'm not sure i'll really be able to take full advantage. I'm pretty competitive when gaming, a lot of fps fast paced games. Could I make the jump? Or would I be better off at 144hz @ 1440p? Thanks in advance! My system specs are as follows: CPU: core i7 8700k...