The current HDMI card supports up to HDMI 2.0b, which means it supports a maximum bandwidth of 14.4 Gbps and does not support any compression.
14.4 Gbps is enough to run 4k 51 Hz, 1440p 109 Hz, or 1080p 185 Hz with standard blanking, 24 bit color depth, and without any chroma subsampling.
Blanking is bandwidth that is deliberately wasted for monitor compatibility reasons, color depth is how much data is used to specify the color (higher depth = more unique colors but more bandwidth needed), and chroma subsampling is a bandwidth saving technique where color data is only sent for some of the pixels while other pixels are limited to only brightness data (hurting quality).
An HDMI 2.1 card could enable much higher bandwidth as well as add support for Display Stream Compression (DSC). DSC is a visually lossless compression algorithm, which means that it technically reduces quality but not by a significant enough amount to be noticable to humans.
The current HDMI card uses the Parade PS186 chip to translate DisplayPort signals from the laptop into HDMI 2.0b signals. The PS186 chip has a successor: The PS196.
The PS196 supports HDMI 2.1. It is limited to 25.92 Gbps of uncompressed bandwidth (60.75% as much as the HDMI 2.1 spec allows) however with DSC it is capable of compressing up to a 77.76 Gbps display signal into that 25.92 Gbps at near full quality.
That enables over 8k 60 Hz with standard blanking, 24 bit color depth, and no chroma subsampling.
Other chips besides the PS196 could also be used of course, I am merely suggesting it because it is the successor to the PS186.
i think theres some problems that would arise with a usb c + something else combo card, from what i remember i think it would be impossible to support usb-4, usb pd, and usb dp alt mode with that. id say the best one would be usb-a plus an audio jack, because usb-a lets you connect quite a lot of things still, and it means you dont take up a whole 1/6th of your io with an audio jack
id also love a dual usb a card, but i think it would at best just about fit, which would take a lot of time to research and develop (i think a similar problem of something just about fitting was going on with the full size sd adapter which is why that took so long)
i think framework should also lean a bit more into those larger cards like the ethernet one, since i feel more people will be open to them if its a couple ports like that and not just the one for ethernet, it could also open up some more possibilities, such as less worrying about physical space for dual (or even triple) port cards, and could also add the option for an nvme m.2 2230/2242 card (like a diy storage expansion card, it wouldnt obsolete those as the main benefit of those is the smaller form factor)
I’d like to see a 1 Gig ethernet card, possibly with a fold-down mechanism like on Dells, Lenovos etc. I know these can be flimsy but that’s on us to look after them. I’d just like to see an ethernet card that can be left in the device while travelling without sticking out the side like the 2.5 Gig.
In fact community members have already made dual USB-A cards by taking existing USB splitters and modifying them to fit (similar to how people were taking SD card readers and filing them down to fit before Framework announced their official one).
IMO the big problem is that the USB-A ports would be so close side to side that many USB-A plugs being plugged in would block the other port.
That’s been in the works, see Josh Cook's dual USB-C expansion card. Unfortunately it looks like the board designers/makers that he was talking with who were doing the work have flaked and ghosted him. sigh So for now, back to nothing. We’ll see what happens, he might have to go find some other design shop, or end up having to refund the pre-orders. I hope not. I really want a dual USB-C.
I can’t believe I didn’t say this first thing years ago. I’ve ALWAYS wished for this since I use kvms and crash-carts a lot and it’s super annoying. The best option these days is pikvm but that requires a power source and network setup. Previously it was SpiderLinx, an expensive commercial thing that does the same as pikvm.
Essentially hdmi capture and usb client.
aka Nexdock or CrowView, but if the Nexdock was actually a full laptop instead of just a kvm.
It would need 2 physical ports crammed into the slot, and that means annoying mini-hdmi or micro-hdmi like on pi’s. But they do exist and thanks to pi’s you can actually buy adapter cables.
Or, actually I would be ok with a solution that used 2 slots. One for hdmi input and one for usb output. I would rather that than need special adapter cables since that’s just another kind of special dongle even if it doesn’t have electronics, a special cable is still an external part that must be present or else the feature isn’t usable.
Alternative to NexDock/CrowView which are dedicated whole kvm devices, GPD pocket 3 is a full (if small) laptop with an optional kvm module. https://www.gpd.hk/gpdpocket3
Welcome to the forum! TLDR, not really with the IO structure of the laptop, iirc the thing that prevents that is using usb4/TB4 for all of the ports that go into the adapter
It might be possible to build an HDMI capture device into an expansion card.
You could then either just display the stream or even composite/record it on the laptop. On the other hand, there will be a lot more latency than if you had a native HDMI input to the screen.
There have been some ridiculously tiny KVM devices recently which provide HDMI signal capture among other things.
Perhaps, but say that you were to solder wires directly to the display board, and then perhaps those to pogo pins on the card? All wildly hypothetical btw
You can do a lot if you’re willing to invest enough effort. But there is the question of if it’s worth it.
I think feeding directly into the display would have problems. And just tapping in would be a lot of effort to begin with. The display cables aren’t made up of plain wires. Each wire is micro-coax to maintain signal integrity. That’s not easy to solder. In addition, laptop motherboard display connectors don’t follow a standard pinout, so the cables are custom. You can’t just buy a splitter cable compatible with the FW mainboard connector.