
USB 4.0 [pdf] - kalium-xyz
https://www.usb.org/sites/default/files/2019-09/USB-IF_USB4%20spec%20announcement_FINAL.pdf
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chx
This needs a 2019 in the title.

This is a little more than USB 3.2 2x2 + TB3 but there's one crucial
difference: the new, still optional USB 4 Gen 3 (what TB3 was) now carries USB
packets as well. Previously TB3 only carried PCI Express and DisplayPort
packets and the Intel hubs had USB root hubs in them. This solution worked out
so well some PCIe enclosures opted to use two TB3 controllers just to get a
problem free USB experience...

Also, PCIe was nerfed by Intel in TB3 for unknown reasons to 22Gbps, there's
hope it'll be 32Gbps this time for real. You can still run a 3440 x 1440 @ 60
Hz monitor on the remaining bandwidth (or to spew marketing BS, 4k @ 30 Hz).

~~~
crooked-v
> USB 4 Gen 3

Are they going to do that thing again where they rebrand the existing
standards from USB 3 Gen X to USB 4 Gen X?

~~~
ksec
Yes they are, at least for now.

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blackrock
I would actually like a Type C sized USB port that is magnetic.

Kind of like the magnetic Apple charger for the older MacBook.

Why magnetic? So that I can quickly attach and detach a flash drive to it,
without actually plugging it in. And then have an external mechanical locking
pin or mechanism, to hold the device or cable in place, if you need to better
secure it.

Why would this be superior?

* You eliminate the actual wear and tear of the USB metal housing.

* The external locking mechanism can be easily repaired or replaced when it wears out or breaks.

* It would probably help make your computer more waterproof.

~~~
Rebelgecko
There's some magnetic USB-c adapters you can get on Amazon. They kinda look
like pogo pins

~~~
beagle3
I was under the impression these only work for usb c power distribution; do
they also work for data, display, etc?

~~~
latentpot
Yes. Some have only 2 leads, but the newer ones have all of them.

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joecool1029
This is from Sep 2019, HN discussed it here:
[https://news.ycombinator.com/item?id=20870326](https://news.ycombinator.com/item?id=20870326)

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vearwhershuh
Does anyone knowledgeable know if a magnetic coupling is coming for USB?

I have used volta cables for a while (I preferred the 1.0 to the 2.0) and I'm
surprised that this design idea isn't more widely popular, given how user
friendly it is.

~~~
Holkin
USB-IF has no plans to include magnetic retention in the spec for USB. The
onus is on manufacturers to implement this on their devices and cables if they
wish for this to become a recurring feature on the market. There might be a
more detailed reason as to why and if you want, I can seek an official
response from the USB-IF team and their association management company, VTM
Group.

~~~
pininja
Thank you for the offer. It would be interesting to hear their response. It’s
seems there are a lot of people who like magnetic retention. I miss MagSafe :)

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3fe9a03ccd14ca5
Tldr

• Two-lane operation using existing USB Type-C® cables and up to 40Gbps
operation over 40Gbps certified cables

• Multiple data and display protocols that efficiently share the maximum
aggregate bandwidth

• Backward compatibility with USB 3.2, USB 2.0 and Thunderbolt

~~~
dieselerator
Thank you. I appreciate the summary.

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Causality1
God I miss the days when I could tell what a port was capable of by looking at
it.

~~~
Dylan16807
What ports are you thinking of? PS/2, parallel, serial, VGA, HDMI,
DisplayPort, Ethernet, USB since 2001... they can all vary in capability. DVI
might not? But you have to look really closely to make sure you have the right
_kind_ of DVI.

~~~
mmastrac
DVI is a pain! Is it analog only? Digital only? Dual link capable?

So glad that HDMI superceded that one.

~~~
zvrba
Yeah, about HDMI... why did DisplayPort get invented?

~~~
akvadrako
higher performance, simpler, can be used internally and royalty free

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PaulHoule
This particular document doesn't communicate value to the consumer. I have
much love for USB 1, 2, 3 and if were not for those USB-C connectors that
don't seem well connected to the circuit board I'd be satisfied.

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knolax
I always get a little surprised when I see the new USB logo on things. It just
looks so stylistically different from the old trident + "USB" logo that it's
jarring.

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toastal
I want to start seeing these USB4 ports in laptops though to free us up from
Intel+Thunderbolt.

~~~
teilo
Huh? Intel invented Thunderbolt. USB4 _is_ Thunderbolt 3.

~~~
cesarb
> USB4 is Thunderbolt 3

No, USB4 is a successor of Thunderbolt 3 (but similar enough that it can be
backwards compatible with Thunderbolt 3). For instance, Thunderbolt 3 tunnels
only PCIe and DisplayPort, while USB4 also tunnels USB 3.x.

~~~
DiabloD3
I agree with this analysis.

USB4 is more of a Thunderbolt 4. Not only can it tunnel USB natively, it seems
likely to be supporting a newer higher speed higher than TB3's 40gbps (but if
it don't, I'm still happy with 40).

