In plain language
The chain from controller to screen has several stages: the source renders, the signal travels, the display processes, the panel lights up. The travelling part is essentially instant. The processing part is where the milliseconds go.
A television in film mode can add 80 to 120 milliseconds. The same set in game mode often drops below 20. That single setting outweighs everything else in the chain.
Why it matters in your setup
People add devices to an HDMI chain and worry about the latency each one contributes. For a pass-through device the honest figure is negligible — a few pixel clocks, far below the threshold of perception. Worrying about it while the television is in film mode is looking in the wrong place.
The things that genuinely matter are game mode (ideally automatic via ALLM), VRR, and the refresh rate the chain negotiated.
What the DR HDMI 8K does with it
The DR HDMI 8K specifies input lag below 1 millisecond, described in the manual as only a few pixel clocks — nothing noticeable. What it can do for latency is indirect but larger: making sure ALLM and VRR are actually advertised to the source, so the display switches itself into the mode that saves you 80 milliseconds.
Need the hardware?
Open the DR HDMI 8K product page on HDfury.uk.