Does HDR10+ GAMING only work over HDMI?

No. HDR10+ GAMING is not limited to HDMI by design — the specification supports any digital display interface, including HDMI, DisplayPort, and cloud-gaming APIs. Today’s HDMI-only experience is a current limitation of GPU support, not of the standard itself.

Where HDMI is used, HDR10+ GAMING requires only HDMI 2.0 or later — not HDMI 2.1; we have seen that version number getting associated with HDR10+ GAMING because HDMI 2.1’s extra bandwidth is needed for 4K/120Hz gaming in general, a separate requirement from anything HDR10+ GAMING’s own signaling needs.