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The situation with HDMI is confusing enough without also introducting USB-C into the picture.

A lot of video cards and some monitors will negotiate a DisplayPort link over HDMI ports and HDMI cables.

For instance, my Intel NUC has only a single HDMI port, but plug a HDMI to DisplayPort cable in, and it'll negotiate a DisplayPort 1.2 connection to my Dell U2711 at 2560x1440@60hz. Plug a HDMI to HDMI cable in, and plug into the HDMI port on the same monitor - no bueno, it's HDMI only and we're stuck at 1920x1200.

Another monitor, I forget the brand, was happy to negotiate DisplayPort over a HDMI port.

Introducing USB-C adapters into the mix and some adapters appear to support USB-C Alternate Mode to carry DisplayPort but only have HDMI connectors, others won't.

Then we run into potential issues where the video card's outputs may not have been wired into the USB-C controller. Though this afaict is mostly applicable to desktops with discrete GPUs.

That’s kind of really cool on a technical level while also being strange and confusing.

Displayport has an extension called dual mode which basically all modern dp devices support which lets them use passive converter cables to hdmi and dvi. Usually you get a displayport port and you convert to hdmi. This must a displayport chip connected to a hdmi port which is pretty whacky but I can't see any reason why it couldn't be done.

> Apple USB-C Multiport adapter simply refuses 60Hz 4K

Don't know if it's the case for you: the older version of the adapter was limited to 30Hz @ 4K. Only the latest version supports 60Hz @ 4K.

I have both and unfortunately they look very similar. Only the fineprint gives a clue which is the newer version.

https://support.apple.com/en-us/HT207806

That would make sense, I bought mine in 2016 when it was “discounted” to make us feel less bad about losing ports.

This would then be the old 30hz @ 4k version. Infos about the release of the 60Hz @ 4k version:

https://9to5mac.com/2019/08/08/new-apple-usb-c-digital-av-mu...

> I can’t for the life of me figure out why the people who make displays with built in power supplies for USB-C charging didn’t just default it on the 100W maximum that the spec allows

I asked myself the same question, and I guess it is either one of the following:

a) 65W is what the reasonably priced chipsets available on the market support, and it would take a lot of costly auxiliary parts to support 100W

b) its a heat management problem

I'm not on a Mac anymore, but this sounds very similar to something that I experienced when switching over to Linux and trying to use the Apple adapters that I had for my displays.

I can't remember the exact terminology, but there are basically two types of adapters: active and passive. Passive adapters defer some of the work to software on the computer while active have everything needed built in.

All Apple adapters are passive and because of that when you try to use them with non-Apple computers that don't have the expected software/driver...they don't work.

It's been a while but I experienced this with mini-display port to DVI adapters. I don't know if it carriers over to other types as well.

Honestly that might be why the adapter is relatively cheap.

A lot of other solutions especially if you need single cable operation and >65W or especially 96W charging for the 16” MacBook Pro are active hubs that cost well over $100.

But those are all cheaper and more flexible and cross platform than buying the 27” UltraFine display. My eyes can’t tell the difference between the UltraFine and the 4K 27” LG display that cost me $290.

Another thing is whether or not a DisplayPort connector (or mini DisplayPort) supports 'dual mode' DisplayPort.

Many graphics cards have these, but it's VERY unclearly marked on most things.

See: https://en.wikipedia.org/wiki/DisplayPort#DisplayPort_dual-m...

If you have a DP++ port, then it can basically act as an HDMI port with a passive adapter. If not... well, tough luck.

It's interesting, at least the lightning to HDMI adapter from apple dynamically loads a bundled copy of iOS from the device itself. I'm unsure if the USB-C multi port adapter is similar. https://hackaday.com/2019/07/30/apple-lightning-video-adapto...

It doesn't seem to be dynamically loaded the same way, but it certainly has software updates: https://support.apple.com/en-us/HT205858.

Darwin with SecureBoot, not iOS.

> Frustratingly, Apple doesn’t make a similar USB/power/video adapter for DisplayPort...

I use just a cheap USB-C - DP cable for this. Works fine. Of course no USB ports and can't charge with that, but not a huge issue since there are more ports.

Yeah that’s what I ended up doing as well, although mine is a USB-C to HDMI adapter.

My display has two HDMI and one DisplayPort, so I’ve allocated one HDMI for USB-C Macs, one HDMI for the desktop Windows PC, and one DisplayPort for Mini DisplayPort devices (2015 MacBook Pro).

In my opinion, buying a two-port MacBook Pro of any kind is a mistake for this very reason, although I guess more adapters can solve that problem...

>be careful here as a 2016 USB-C MacBook Pro 15” doesn’t support 4K 60Hz over HDMI

Yes it does. I use it every day. Might be your adapter.

A lot depends on the HDMI version (and in somce cases HDCP)

also in some cases, even with the right adapter, which type-c port you plug it into;

https://apple.stackexchange.com/a/354688

Interesting. I have a 15" with the upgraded GPU so that might be why I avoided some of these weird issues.

The bigger part of your problems will go away if you do yourself a favor and refrain from tge end-consumer hostile decisions the comoany in cupertino will take for you.

Hmm well it’s not like every laptop or adapter that has HDMI involved is guaranteed to support HDMI 2.0, either. I’m not sure how this is an example of Apple doing something user-hostile. It’s an example of two similar industry standards existing and having different levels of capability at different times.

Plenty of non-Apple products don’t support 4K 60Hz and plenty of non-Apple laptops require some kind of adapter to connect to a full size HDMI port, like the current XPS 13.

In fact, Apple switching to USB-C was moving from a proprietary connector (MagSafe) to an industry standard. So I’m struggling to figure out how that’s user-hostile. It’s better than all the business laptops with proprietary dock ports or the proprietary surface connector.

I guess it sucks that I was an early adopter and I got the early adapter but on the other hand 4K displays weren’t anywhere near affordable in 2016.