What Is GPMI, The Potential New Successor To HDMI?

If all that sounds like a bunch of vaguely familiar random letters to you, though, here’s why it’s important.

What is HDMI?

HDMI stands for High-Definition Multimedia Interface, and if you’ve ever set up… well, just about anything with a screen, really – a TV, a monitor, a projection screen for a presentation, whatever – then you’re probably familiar. They look like this: 

They’ve been around since 2002 in some form or another, though the exact specification has been updated as technology has progressed – the most recent version, HDMI 2.2, for example, can handle 96 gigabits of information transfer per second (Gbps), which is a vast improvement from 2002’s 4.95 Gbps.

Originally, they were quite the innovation. Society had only just made the switch to digital rather than analog connectors, and the most popular way to link up your cutting-edge screens was via a DVI cable. 

These worked okay – they still do, in fact, in devices old enough to support them – but HDMI had advantages that made its takeover all but inevitable: it supported both audio and visual components, rather than DVI’s visual only; it could be linked up with CEC (Consumer Electronics Control), allowing devices to communicate across manufacturers and components; it came in one basically universal option; and perhaps most impactfully, it had integrated digital copyright technology – and thus the backing of major media companies.

“HDMI is the first video and audio standard to amass support from the entire CE [consumer electronics] value chain, from content providers to system operators to CE manufacturers,” Wanda Meloni, then president of digital media technology company M2 Research, said in a statement back at the launch of HDMI. “Consumers have been eagerly awaiting more compelling high-definition content, and HDMI should unlock the floodgate.”

Still, though, the connectors weren’t perfect. They were proprietary hardware, meaning that manufacturers had to pay to include them – and as our TVs and PCs get ever higher specs, some are already worrying that even 96 Gbps won’t be enough pretty soon.

What is GPMI?

Enter the GPMI – or to use its full name: the General Purpose Media Interface. Announced earlier this month by China’s Shenzhen 8K UHD Video Industry Cooperation Alliance, this cable interface standard can reportedly support up to 192 Gbps of video and audio – twice that of the still yet-to-be-released HDMI 2.2 – as well as delivering both data and up to 480 watts of power supply. For those keeping count, that makes it even more of an all-in-one solution than the HDMI cables it may replace.

Like HDMI, it’s backed by industry giants like Huawei, Hisense, and TCL – though, notably, none outside of China. It’s also obtained official approval from the USB Association, according to Hong Kong’s HKEPC, so it shouldn’t have compatibility issues with the hardware already in use.

That said, there’s not nothing new going on here. Alongside the USB-C type GPMI cable is a new, proprietary, “Type-B” cable, and it’s this that has the headline-grabbing 192 Gbps/480W capacity – the USB-C connector only manages half of each. Why that is, exactly, is unclear – whether it’s because USB-C literally can’t cope with such high transfer rates; to ensure USB 4 compatibility; or if it’s just a tactical move to establish the kind of iron grip in the market that HDMI has so far enjoyed, is not yet established.

Either way, GPMI evidently has quite a few advantages over its predecessors, assuming everything ends up working out. Even if only the USB-C connector gets taken up, with its identical transfer rate to the upcoming HDMI 2.2, there’s still the power-sharing benefit, as well as a touted potential for “daisy chain networking technology”, per semiconductor company HiSilicon, one of those championing the new standard, and support for two-way control systems. Presumably, being non-proprietary, it’ll also be a bit cheaper to include, which might make it more tempting for manufacturers.

“GPMI is an innovative achievement and a core technological breakthrough in the audio and video industry,” said HiSilicon in a translated statement. “It integrates the functions of video transmission, data interaction, network connection and power supply, and realizes that one interface can support the full business needs of ‘audio and video + data + network + control + power supply’.”

Which just leaves one question: when should we expect to see these new cables roll out?

Do we need to buy all new cables now?

Short answer: probably not. 

Long answer: all we have is a few announcements right now, and even if everything works out without a single hitch, we still should expect a reasonable wait before compatible products start turning up in stores. After all, it took close to two years for consumer HDMI products to reach the shelves back in 2002-3 – and while there’s been noise about “multiple product prototypes” being released “within the year”, no specific products have yet been announced that will incorporate it.

But, frankly, “without a single hitch” is not a given here. So far, this tech is not being embraced outside of China, and it’s unclear how enthusiastic Western companies are going to be about adopting it. GPMI will reportedly initially prioritize “home entertainment devices” like TVs – but big names like LG, Samsung, and Sony haven’t committed, and those three combined make up a full 50 percent of the global TV market.

And amongst all these potential snags, there’s one factor that can’t be overlooked: as it stands, HDMI and USB-C are… fine? Okay, GPMI has advantages, but they’re not necessarily gamechangers over the status quo – especially from the point of view of manufacturers and media companies.

Basically, this announcement is tantalizing for nerds (affectionate) – but not a reason to go out and replace all the devices and cables in your house right now. Give it five years, though, when we’re all rocking 256K 7680Hz interactive surround-sound smellovision TVs in our living rooms – well, then we might need to switch to GPMI.