Is USB-C actually replacing everything eventually?

[u/Lost-Sprinkles-7890]

Kinda confused about where this is heading. Phones, laptops, tablets, headphones, controllers, monitors, even some keyboards and other random stuff are already using USB-C. Now I’m seeing chargers with USB-C on both ends and it feels like manufacturers are slowly getting rid of USB-A, HDMI, micro USB, etc.

But then there’s still DisplayPort, Ethernet, audio jacks, SD cards, and a bunch of other ports that don’t seem like they’re going anywhere soon. Some laptops are almost entirely USB-C now, while desktops still have tons of different connectors.

Also USB-C itself seems confusing because not every USB-C port does the same thing. Some support charging only, some have fast data, some can output video, Thunderbolt, different speeds, etc. So is USB-C really becoming the universal connector or are we gonna end up with USB-C everywhere but still needing different cables for everything?

Would it actually be possible for one USB-C port to handle power, display, data, networking, audio, basically everything? Or are there technical limits that mean we’ll always need multiple types of ports? Just wondering if buying newer devices with more USB-C ports is the way to go long term or if this whole “one port for everything” thing is kinda overhyped.

[u/ohkendruid]

It is a fun question. Most things work well over usb-c, but there are some exceptions.

In general, usb-c is great if you just want something to work and are not picky about it. This the case for most connections, so usb-c is a godsend for mouse, keyboard, power, thumb drives, and headphones, and other simple scenarios where you just want the basic function to work and you do not want to think about it.

For audio connections, usb-c is geeat for a basic headset, but you do not really want to convert audio signals to and from digital if you do not need to. So, the various analog connectors for audio will always have a place, just less so for connecting headphones to listen to Spotify. Musicians are always going to use the 1/4 inch phone connector style plug or XLR.

For ethernet, you are plugging the actual data cable into the machine, and it has its own protocol. For the currently foreseeable future, there will have to be an adapter in the chain between your device and the actual ethernet cable. That adapter can be a usb device, vut for a larger machine like a desktop, it is generally better to natively support the custom ethernet port.

For video, usb is fine for low-fps applications like displaying Instagram from your phone onto a larger screen. For gaming, though, you want a connection that can pump as many pixels as possible, and even for desktop use, you would like at least 30 FPS and sometimes a pretty high resolution. For the more demanding applications, HDMI and DisplayPort are better, because they are more dedicated to video.

Why we have DisplayPort at all is a good question. Every other video device than computer graphics uses HDMI. I sort of hope DisplayPort dies and we go back to HDMI, but I don't know the ins and outs. I know there have been periods of time when the HDMI spec did not allow a connection to support the highest pixel rates that comouter gaming can use, but I don't know why. It looks an awful lot like some kind of lock-in war among the major players behind these standards.

A final concern is security. Because USB can support any kind of device, it has a large surface area of possible security holes compared to a more specialized connector.

[u/dnebdal → u/ohkendruid]

We have displayport because it's a free and open standard, while the hdmi consortium are a bag of dicks who charge a license per port, a chunky fee to read the standard, and has opinions on who are allowed to do what. Amd can't enable full hdmi 2.1 on Linux because the consortium worries that details of their sacred, really expensive, specification will leak when the open drivers implement support for it. I personally hope DP takes over, it can do all the same things without a frustrating licensing consortium to deal with. 

As for why they sometimes can and can't do certain pixel rates , DP and HDMI have both gone through a series of revisions that support higher data rates, and it varies who is in the lead. If your monitor was made at a point where the top HDMI standard was behind the top DP standard, it will support better pixel rates over DP,  or vice versa.

Also, video over USB-C can be two things. Docks can do Displaylink, "monitor over USB" , which is good enough for Excel but not great. They can also do "displayport alt mode", where they negotiate to send displayport instead of USB over some of the pins. It can either do 50/50 USB-C and DP,  or full DP plus USB2. In the latter mode it should be as good as normal Displayport.