I am using VGA recently, because while my old dell had HDMI and DVI, the new HP has only VGA and DP on the docking station.
Im going to get a DP cable and try that... Thing is, this monitor has appeared grainy and strained my eyes even when connected with DVI on my old dell. I think it is a function of the PWM backlight (dell is well known for flicker apparently) and their thick anti-glare coating.