Viewsonic VX2880ML 1440p 60Hz

[theProbe]

Hello, i'm in need of help.
I bought this monitor because of the deal (non advertised open box, half the price) being cheaper by a lot than the cheapest 1440p monitor. So i bought this 4k 30Hz monitor to use it as a 1440p 60Hz monitor but i can't figure out how to configure it so that it is 60Hz.

Apart from this i get some inconsistent and non periodic pink flashing, horizontal lines from the right side and display doesn't wake up properly after sleep or when it randomly goes off(after which it displays dp link error and makes usb plugnplay sound). It is connected to 270x with a dp1.2 cable(yes i enabled the 1.2 on display aswell).

So is it possible that a faulty cable is causing all these problems and not alowing me to use 60Hz on 1440p?

Using W8.1, z87 system.
Thank you

- i could have ben more specific but the text would have ben too long. I think i mentioned all the crucial information.

 

[theProbe]

Okey i partially solved my problem, the dp cable is faulty for not letting me set 1440p and 60hz. But still, after switching from dp1.2 to hdmi 1.4 with high speed hdmi i still get the pink flashing in the bottom half of my screen but much less frequently.