The G-Sync HDR system requirements themselves are described rather minimally:
https://www.anandtech.com/show/12941/nvidia-publishes-gsync-hdr-sys-reqs-releases-vbios-update-tool
- Windows 10
- NVIDIA GeForce GTX 1050 or higher (desktop GPUs may need firmware upgrade)
- R396 GA2 driver or higher (presumably 397.64 and higher)
- DisplayPort 1.4 driven directly by the GPU
In preparation for these new displays, towards the end of this week NVIDIA quietly published official G-Sync HDR System Requirements, which links to the newly-released Graphics Firmware Update Tool for DisplayPort 1.3 and 1.4 Displays. The latter applies to a range of Maxwell and desktop Pascal products, but more importantly is there to provide G-Sync HDR capability for older Pascal cards that shipped without an HDR-supporting VBIOS.