Dual monitors

@francescorossato  Yes, you can use the Mini-DisplayPort and HDMI outputs simultaneously.  In terms of capabilities, unfortunately Dell's Setup and Specifications document for that system doesn't specify the HDMI and DP revisions supported by those ports, but based on the age of the system, the DP output would support at least DP 1.2 for 4K 60 Hz and the HDMI output would support at least HDMI 1.4 for QHD/1440p 60 Hz (or 4K 30 Hz).  It's possible that the Mini-DP output would support DP 1.4 for up to 5K 60 Hz (or 8K 30 Hz) and that the HDMI output would support HDMI 2.0 for up to 4K 60 Hz, but those seem less likely.  And in order to run anything above 4K 60 Hz, you'd need to enable a BIOS option that allows the discrete GPU to take direct control of the display outputs.  By default, the Intel GPU controls the display outputs and the NVIDIA GPU operates only when its performance is needed, and then only as a render-only device through a technology called NVIDIA Optimus.

If you do decide you want a dock, the only fully functional choice would be the WD19DC (or technically its predecessor the TB18DC, but that's outdated now).  Those are the only docks that can supply the amount of power needed to run your system optimally since they connect to two USB-C/TB3 ports on the system.  Other docks won't provide that much power, so if you used them, you'd have to connect your system's power supply directly as well if you wanted to maintain optimal performance.

@francescorossato Ah ok, I was looking at that document in the section that showed the rear of the system and labeled the ports there. Normally more information is provided there, but not on this one. I didn’t jump down to the specifications table section.

The multiple interface portion refers only to using multiple interfaces to drive a single display. That is a very rare setup and only occurs with 8K 60 Hz displays and previously with 5K 60 Hz displays before DP 1.4 arrived, since in that case dual DP 1.2 interfaces was required. But it would NOT mean that those ports can ONLY be combined to run a single display, in fact it would not be possible to mix mDP and HDMI to run the same display. My expectation is that you would be able to use mDP, HDMI, and USB-C/TB3 all simultaneously to run 3 separate displays if you wanted to do that. There are some Latitude laptops that have 3 video output connectors but only allow 2 of them to be used at the same time, but I would be very surprised if a limitation like that existed on a Precision 7000 Series system.

Another possibility is running multiple displays just from one port. The mDP and USB-C ports both use DisplayPort protocol for video output, which means you can use them to either create a daisy chain (if you use a display that has a DisplayPort output to set that up) or you can use an MST hub that would give you multiple outputs even though it only connects to a single port on the system. I have two Dell U2717D displays that I run as a daisy chain. However, when using a daisy chain, the bandwidth requirements of the entire chain must be within what that single output can support. It’s just a convenient setup because it means you only have to deal with one cable connected to the system rather than two.