I'm pretty sure most dell laptops have mini DP. My desktop grapics card also has two mini DP ports which I used with a DP to DVI cable without adapter. (something like https://www.amazon.com/SIIG-DisplayPort-Converter-Cable-CB-D...) You need an active adapter if you want dual link dvi though.
The most recent graphics cards (1080/1070) have 3 DP ports, one HDMI, and one DVI. Also, every laptop I own/use/know of has a mini-DP port too, across roughly 4 brands.
HDMI got their foot in the door first, but I think we'll be seeing more DP stuff in the very near future. The only downside of DP is the cables are usually more expensive.
