HDMI doesn't exist to me in the PC ecosystem until 2.1 so I don't know about hdmi support at all. DP has been the standard in monitors and PCs for some time, and to my knowledge and experience the vast majority of freesync monitors will support adaptive sync with Nvidia cards to some degree over Displayport connections. Issues like flickering, reduced brightness, or broken support are another kettle of fish and why nvidia have their certified list. "Other GPUs, such as the Nvidia GeForce 10 series and newer, that support DisplayPort Adaptive-Sync, are also expected to work with AMD FreeSync Technology; please check with your GPU manufacturer." Straight from AMD's mouth. If people are using hdmi cables with their monitors then that's a whole other kettle of fish I have never looked into.