I already have three monitors set up using an R9 270x with the HDMI port taken and also the display port connector however i am using an active display port to HDMI and i am also using one of the dvi ports on the back of the monitor. however when i go and plug in another dvi to HDMI cable in, it doesn't show is this because i need another active dvi to HDMI cable if so would you be able to link one as i am having trouble finding one!