Quotethe Geekom A9 Max offers a modern connection option for screens with HDMI 2.1.
A recent comment somewhere on this site said that Geekom said that the HDMI 2.1 is HDMI 2.1 FRL 24G, not the full FRL 48G. 24 GB/s are not enough if you want to connect a 4K 120Hz 8-bit display, let alone a 10-bit one for HDR, which requires FRL 40G [for 120 Hz, and 48G for 144 Hz] (in a search engine type 'HMDI 2.1 bandwidth calculator').
The HDMI Forum allows to rename "HDMI 2.0" to "HDMI 2.1". Only "HDMI 2.1a" is true 40G or 48G. This concerns all mini-PCs without a dedicated GPU.
en.wikipedia.org/wiki/HDMI#Refresh_frequency_limits_for_common_resolutions