vertical lines go down screen when i use 120Hz

[Brachaboy]

When i set 120Hz in the nvidea control panel my screen has lots of vertical lines going down it, i have a EIZO floris fg4241 and a evga gtx 970, using DVI to connect them. I dont have 120hz set in windows, as when i do that i get a dvi signal error. Thanks

 

[SkyNetRising]

You need dual link DVI cable for 120hz operation.
Either yours is not dual link or is of poor quality.