These discrete cards based on the DG1 GPU were designed for use by system integrators on their systems. Intel let us know that the Iris Xe discrete add-in card
is currently only compatible on 9th Gen (Coffee Lake-S) and 10th Gen (Comet Lake-S) processors on select chipset-based motherboards. A special UEFI is needed for the motherboard that supports Intel Iris Xe.
The full response to our question about getting our hands on a review sample can be read below.
The Iris Xe discrete add-in card will be paired with 9th gen (Coffee Lake-S) and 10th gen (Comet Lake-S) Intel® Core™ desktop processors and Intel(R) B460, H410, B365, and H310C chipset-based motherboards and sold as part of pre-built systems. These motherboards require a special BIOS that supports Intel Iris Xe, so the cards won’t be compatible with other systems.