New HDMI 2.1 Specification Supports Higher Resolutions, Refresh Rates, and Game Mode VRR

Subject: General Tech | January 6, 2017 - 04:22 AM |
Tagged: vrr, variable refresh rate, HDMI 2.1, hdmi, g-sync, freesync, adaptive sync, 48G

The HDMI Forum has introduced an update to the HDMI specification, bringing the video standard to version 2.1. The updated specification, along with its accompanying new "48G" (48 Gbps) HDMI cable, brings support for higher resolutions refresh rates, and color spaces along with new features such as dynamic HDR, a variable refresh rate "Game Mode VRR", and eARC for audio device detection and object oriented audio (e.g. Dolby Atmos). 

HDMI Cable.jpg

Specifically, HDMI 2.1 adds support for 8K resolutions at up to 60 Hz and 4K at up to 120 Hz along with HDR (high dynamic range). The specification is even a bit future looking in that it allegedly supports 10K50/60/100/120 modes! The 8K@60 and 4K@120 (and higher) profiles do require the new 48 Gbps cable though lower resolutions can still get by with the older High Speed cable. The specification also supports BT2020 color spaces with 10, 12, and 16 bits per color component which I expect Ken and Allyn will appreciate.

Perhaps the most interesting new feature though is the Game Mode VRR which appears to be HDMI's take on DisplayPort's Adaptive Sync (which AMD uses for FreeSync). At last year's CES AMD was showing off FreeSync over HDMI (video) with AMD doing FreeSync over HDMI as an extension of the specification. It now appears that HDMI is rolling some manner of that variable refresh technology into the base HDMI 2.1 specification. Variable refresh rates being supported with HDMI is a good thing as it means that future game consoles may see their own FreeSync/G-Sync like variable display output options as I do not see game consoles and living room devices (TVs, receivers, et al) adopting DisplayPort any time soon if only because of the huge install base and foothold HDMI has on that market.

Notably, HDMI 2.1 remains backwards compatible with earlier specifications, cables, and devices based on older HDMI standards including the Ethernet channel and inter-device communication. Existing devices will be able to use HDMI 2.1's 48 Gbps cables but will not be forwards compatible with all of the new features (though partial new feature support might be possible with firmware updates though in no way guaranteed).

The new specification is expected to officially drop in early Q2 2017 at which point it will be available to all HDMI Adopters for testing.

I estimate that, following the compliance testing and device QA, products using the new specification should start shipping as soon as next year (at CES 2018 perhaps!). It is harder to say when graphics cards or game consoles will start supporting the new output though. I would hope that AMD and NVIDIA would be able to sneak it in before Vega and Volta based cards launch respectively but the timing may not have lined up like that. And on the game console side of things, Microsoft and Sony have already launched their revised consoles this year save Scorpio so it might be awhile before they sport variable refresh. Perhaps JoshTekk and the crew will have some thoughts on the podcast next week!

What are your thoughts on HDMI 2.1? Will it lay the groundwork for interesting displays and better living room gaming?

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Source: HDMI Forum