The ArsTechnica article said:
There will be two flavours of the controller, one that uses four PCIe 3.0 lanes to drive two Thunderbolt ports, and another version that only uses two PCIe lanes connected to a single Thunderbolt port.
According to
Wikipedia, a single lane of PCIe 3.0 is 7.877Gbps. So four lanes will top out at 31.508Gpbs. Even if the cable can theoretically deliver 40Gbps, there's no way it can actually deliver more than the bus that drives it. In other words, TB3, as it will be implemented this year, is going to top out at about 30Gbps, not 40.
First of all, moving Thunderbolt to USB was inevitable with the advent of USB type C and USB 3.1's alternate stream support.
It's certainly convenient, but inevitable? Because everybody has USB ports? Today, there are probably more devices with Mini DisplayPort connectors than with USB-C connectors. And not just from Apple. One could make a good argument for either connector.
It was mentioned, read again. What was NOT mentioned was HDMI 2.0a, which is worrying. Intel's Alpine Ridge controller was supposed to support it. But on that graph I see all technologies except HDMI ... Does that mean HDMI won't run through USB-C port?
This announcement is talking about Thunderbolt, not USB.
TB3 is supporting DisplayPort 1.2, which means that HDMI 2.0 won't be in there. According to
Wikipedia, DisplayPort 1.3 introduces this capability.
As for USB-C itself, that's a completely different question. It might be possible, but probably not if the port is going to be used to carry ThunderBolt 3.
I think the point is that its not two technologies being merged, more that USB-C was also developed to be nothing more than a port shape.
Absolutely correct. The USB standard is 1.0, 2.0, 3.0, 3.1, etc. Any of them can theoretically be carried via a USB-C connector (and you could get any of them, depending on what speed device you plug in to it.)
Yes, it's confusing, but there's not a whole lot that can be done. The USB standards body defined the connector for use with USB protocols. They developed it with the ability to carry other content along with USB so that (for example) Apple could multiplex power and video. And as a side effect, it can carry just about anything else, including Thunderbolt 3.0. But it's still a USB connector.
The nice thing here is, that if computer makers do it right, that you shouldn't have to care (as much) about where you plug in your devices. If you've got (for example) a power plug, a monitor, a few USB devices and a TB device or two, you can just plug in all the cables randomly to a bunch of USB-C ports and expect it to just work.
I'm sure that in practice, it won't be quite as nice (e.g. only charge the laptop through port 0, only provide TB on ports 1 and 2) but there is at least the potential for doing it the way I described. If there are only a small number of ports, it might even be practical.
Dongles will, unfortunately, be necessary for backward compatibility, but hopefully we'll be able to use cheap passive dongles for most of our devices.
More protocols out of that one connector. More adapters, cables, splitters, and hubs needed to run multiple things. Of course, any adapter with "Thunderbolt" in the name will be crazy expensive.
Maybe, maybe not. According to the article, an active cable (the real expensive kind) should only be needed if you need the 40Gbps speed or extra-long length.
As for the adapter itself, that will depend on what it's doing. A passive adapter (e.g. to a USB-A connector or to a DisplayPort connector) should be pretty cheap. Something that has an embedded device controller (e.g. an Ethernet port) will cost more. And a high-performance device (e.g. a docking station that provides lots of different ports and maybe a hard drive or two) is going to be expensive - but it would be even if the interface was plain USB 3.
Honestly this is kind of confusing to me. I don't fully understand what is referencing the port and what is referencing the connection protocol. Will we start discussing cables in the future by saying "It's a Thunderbolt cable with a USB-C plug"? That's one thing to make it more difficult for consumers to adopt and understand at the mass level.
It's a dual-mode port. USB 3 and Thunderbolt. If you plug in a USB cable, you're going to get just the USB capabilities. If you plug in a TB cable (and have a TB device at the other end), you'll get the TB capabilities.
This shouldn't be any more confusing than TB1/2 and Mini DisplayPort. With those, if you plug in a MiniDP cable, all you get is video. If you plug in a TB cable, then you can get all of TB's capabilities.
The only real potential for confusion will be if a single computer has a whole bunch of USB-C ports, some of which support TB and some don't. Then you'll have to look for markings on the case to know which is which.
According to the experts here on MR, the folks who trust Apple engineers to "know what they are doing", each USB-C port is good for 100W of power -- 20A at 5V!
If I read the article right, that 100W limit is for charging your laptop via USB-C. It will provide 15W to bus-powered peripherals.