XPS 8960, UHD 770 video memory?

The integrated Intel processor graphics hardware doesn't use a separate memory bank for graphics/video. Instead, the Graphics Processing Unit (GPU) uses system memory. The Intel graphics driver works with the operating system (OS) to make the best use of system memory across the Central Processing Units (CPUs) and GPU for a computer’s current workload.

For Intel UHD Graphics 770, the maximum shared memory will be limited by Windows to one-half of system memory.

Reference information from Intel https://www.intel.com/content/www/us/en/support/articles/000020962/graphics.html

Keep in mind that XPS 8960 with UHD Graphics will only have one DP++ port. So you can connect either a DP monitor or an HDMI monitor. DP++ will automatically recognize an HDMI monitor when you use a simple passive DP++(PC)>HDMI(monitor) adapter (not an active adapter).

So if you need to run more than one monitor, you'll need either a DP MST hub with multiple video ports, or at least one monitor that supports DP daisy chaining, or an add-in video card.