4 ms·
When the USB-IF announced that they're going to incorporate Thunderbolt into USB4 I already worried that this might further complicate USB hardware and software
by Dunedan 7y ago
When the USB-IF announced that they're going to incorporate Thunderbolt into USB4 I already worried that this might further complicate USB hardware and software.
Turns out: My worst nightmares just became true. We now have running USB over Thunderbolt. I don't even know where to start facepalming about this clusterfuck.
Take DisplayPort for example: Up to now we had the DisplayPort alternate mode for USB-C. That just worked for most devices with USB-C. Now we also have the tunneling of DisplayPort over Thunderbolt (as Thunderbolt-enabled Macs offer since Apple introduced Thunderbolt in its devices and which they use when connecting to Thunderbolt-enabled monitors). Both methods seem to be optional for USB now, so in future a host and a peripheral device might support "DisplayPort over USB", but while one might only supports the USB-C DisplayPort alternate mode, the other one might only support DisplayPort tunnels over USB4, causing them not to be able to talk DisplayPort to each other.
I guess I'm going to facepalm for a few hours now, while I read the specification in more detail.
- Dunedan 7y ago> A USB4 host and USB4 peripheral device may optionally support TBT3 -Compatability. That sounds good from an implementors point of view, but offers another area of possible incompatibilities for connecting USB4 and Thunderbolt 3 devices. Imagine both devices support tunneling DisplayPort signals, but the USB4 device doesn't support the Thunderbolt 3 compatibility layer: As in the example before they won't be able to establish a DisplayPort connection, while other USB4 devices, which offer Thunderbolt 3 compatibility might.
- tenebrisalietum 7y agoHow is this better than VGA again?
- user5994461 7y agoVGA caps at 2048 pixel wide if we are to believe a quick google search and the fidelity of the image may vary depending on the cable and graphic card in use.
- imtringued 7y agoIt supports multiple 4k screens over one cable.
- jandrese 7y agoVGA has the downsides of the analog signal, like ringing and smearing when you have a higher resolution running over a long cable. DVI ended up being kind of a mess with the different connector types and ultimately fairly limited digital bandwidth. Displayport is pretty good except everything Displayport costs 50% more than it should.
- Izkata 7y agoDisplayPort also seems to randomly stop working, requiring unplugging/replugging the USB to reset it. Occasionally I'll even boot up one morning to find it's not working at all and something or other needs to be reinstalled.
- ProZsolt 7y agoI was a USB-C advocate until this point. I only had problems with the non-compliant devices, and if I buy a cable I have to label it what it capable of. I didn't have a problem that I have to know even if my mouse has a USB-C port it won't support DisplayPort alternate mode, but I reasonably expect if I connect my laptop to a monitor it will be compatible