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M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

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Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#121

Post by goosedragons »

ecshafer wrote: post #110
ramijames wrote: post #82

Earlier quoted context omitted.

The fact that I can't connect more than one monitor to my M1-based iMac is a fucking travesty.

Why can't you? I am typing this from an M1-MPB with two monitors. I just have 1 through thunderbolt and 1 through the hdmi.

You clearly have an M1 Pro or M1 Max MPB since you have an HDMI port. The base M1 models support the built-in display and 1 external display except the M1 Mini that's allowed 1 monitor over HDMI and 1 external display over TB. The Pro, Max and Ultra M1 models allow more displays.

Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#122

Post by specialist »

fock wrote: post #11
nikanj wrote: post #6

USB went from being the universal bus, to just being the universal connector. There are never any guarantees that your device (or cable!) actually supports the operation you’re trying

I'm fine with devices offering different capabilities. But the cables should be marked clearly... I have one of the chinese drawing tablets, which has a convoluted "to USB-C" adapter. Apparently you can also drive it with USB-C directly, however only a manufacturer-provided cable (supershort) fits the port. Noone know what cable you can use alternately...

I'd like an easy way to query, diagnose USB cords.

They now contain their own chips. Right? So there's gotta be some kind of POST. Right?

If so, I should be able to ask the cord what it can do, if it thinks its broken, etc.

Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#123

Post by faller »

grishka wrote: post #48
masklinn wrote: post #29

Earlier quoted context omitted.

> what in the world could "USB 3.1 Gen 2" possibly mean? Versions are free, why not simply name it "USB 3.2" and make the next one 3.3? USB 3.1 Gen 1 is the straight rebranding of USB 3.0, USB 3.1 Gen 2 is the "original" 3.1, which is 3.0 updated to a 10Gbps signalling rate (from 5), and a more efficient encoding (128/132, versus 8/10). But wait, there's worse! USB 3.2 Gen 1 is the same thing as USB 3.1 Gen 1 USB 3.2…

> USB 3.1 Gen 1 is the straight rebranding of USB 3.0 Why? To solve what exactly? In a sane world, it'd be major.minor, with nothing appended at the end. Allowing marketers to take over everything was such a terrible mistake. At this point I myself just don't differentiate USB versions beyond 3.0. 2.0 is the slow one, 3.0 is the fast one, anything newer is "so fast I won't ever saturate this much bandwidth anyway". T…

> Why? To solve what exactly? In a sane world, it'd be major.minor, with nothing appended at the end.

It's always important to get acquainted with a topic before succumbing to the desire to mindlessly criticize in ignorance.

A quick search in Wikipedia shows that USB 3.1 specifies a brand new transfer rate, dubbed SuperSpeed+ transfer mode, "(...)which can transfer data at up to 10 Gbit/s over the existing USB3-type-A and USB-C connectors (1200 MB/s after encoding overhead, more than twice the rate of USB 3.0)".

This is a different transfer mode than the SuperSpeed transfer rate specified in USB 3.0.

To allow implementations to support both transfer speeds, the implementations that supported SuperSpeed transfer rates were dubbed USB 3.1 Gen1, while the implementations that supported SuperSpeed+ transfer rates were dubbed USB 3.1 Gen2.

https://en.wikipedia.org/wiki/USB_3.0

To me that's a very convenient, and customer-centric way of putting together a standard. So there's a minor addition to a major release. Is that left to an annex? No. Do we fork standards? No. We just release a backwards-compatible v3.1 standard that in practice deprecates v3.0 and thus allows the whole industry to avoid piling up the list of current standards that we care about.

Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#124

Post by dylan604 »

uuyi wrote: post #103
ChuckNorris89 wrote: post #83

Earlier quoted context omitted.

Meh, imma wait for USB4, Gen 3.6, 4x4 with HDMI 2.2.1 support. /s

On which HDCP won’t work on televisions manufactured earlier than yesterday.

I think you mean tomorrow. Just keep waiting for it. It'll be worth it. I promise.

Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#125

Post by jsjohnst »

rowanG077 wrote: post #118
jsjohnst wrote: post #76

Earlier quoted context omitted.

Just because it works on an Intel Mac does not mean the cable isn’t the issue! Happy to demonstrate in a live video along with oscilloscope readings to prove it is in fact the cable to blame.

I would like to see this. Mostly to see what kind of an absolute beast of an oscilloscope can keep up with the data rate. Also I don't understand why people are disagreeing with you. If a cable is not within spec it's absolutely possible for it to work in one circumstance because for example the port is more lenient and completely fail with a port that is more strict.

> Mostly to see what kind of an absolute beast of an oscilloscope can keep up with the data rate.

You can prove a cable faulty without being able to fully observe/measure the entire frequency range at once.

> Also I don't understand why people are disagreeing with you. If a cable is not within spec it absolutely possible for it to work in one circumstance because for example the port is more lenient and completely fail with a port that is more strict.

I’m kinda baffled too. I thought this was common knowledge among the folks on HN, but maybe not?

Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#126

Post by grishka »

notatoad wrote: post #113
grishka wrote: post #48

Earlier quoted context omitted.

> USB 3.1 Gen 1 is the straight rebranding of USB 3.0 Why? To solve what exactly? In a sane world, it'd be major.minor, with nothing appended at the end. Allowing marketers to take over everything was such a terrible mistake. At this point I myself just don't differentiate USB versions beyond 3.0. 2.0 is the slow one, 3.0 is the fast one, anything newer is "so fast I won't ever saturate this much bandwidth anyway". T…

IIRC, USB 3.1 was an update to the spec to allow USB Type C connectors. USB 3.0 specified the old type-a connector on one end and one of the weird oversized type-b connectors on the other end. Maybe not relevant as a consumer to have a difference in the spec version for that, but if you’re a manufacturer trying to implement it, it’s worth a bump to the minor version number.

I have some Android phones that have a USB-C port but only support 2.0 speeds (as per the macOS system info USB tree thing). Which version is that then? I've always assumed that the physical layer of the protocol and the connectors themselves were separate specs and you could have USB protocol running over any kind of arbitrarily shaped connector. And no protocol over a USB(-A) connector, because those are de-facto low-power DC outlets now, among other things.

Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#127

Post by jandrese »

faller wrote: post #123
grishka wrote: post #48

Earlier quoted context omitted.

> USB 3.1 Gen 1 is the straight rebranding of USB 3.0 Why? To solve what exactly? In a sane world, it'd be major.minor, with nothing appended at the end. Allowing marketers to take over everything was such a terrible mistake. At this point I myself just don't differentiate USB versions beyond 3.0. 2.0 is the slow one, 3.0 is the fast one, anything newer is "so fast I won't ever saturate this much bandwidth anyway". T…

> Why? To solve what exactly? In a sane world, it'd be major.minor, with nothing appended at the end. It's always important to get acquainted with a topic before succumbing to the desire to mindlessly criticize in ignorance. A quick search in Wikipedia shows that USB 3.1 specifies a brand new transfer rate, dubbed SuperSpeed+ transfer mode , " (...)which can transfer data at up to 10 Gbit/s over the existing USB3-typ…

Adding a new transfer rate seems like a reasonable place to bump the minor version number of a protocol. After reading all of that I'm even more convinced that it should have just been USB 3.2.

Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#128

Post by madeofpalk »

mmastrac wrote: post #116

I find it amusing that every single one of our high-speed standards (ethernet, HDMI, PCIE, displayport, USB) are basically just the same high-speed differential pairs under the hood with different framing. I don't know exactly what we can do about this situation, but at some point it probably makes sense for all of them to converge into a multi-lane, differential-pair standard (or just support nesting each other arbi…

IIRC Thunderbolt essentially is "PCIE but in a cable"

Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#129

Post by shadowfacts »

bombcar wrote: post #95
ChuckNorris89 wrote: post #85

Earlier quoted context omitted.

May I ask why? I assume you were aware of this limitation, as Apple was pretty clear in the specs about it, that it only supports one external monitor. If you pull the trigger on a purchase without reading the specs, then it's pretty much on you, no?

It didn’t become widely known until after the M1s had shipped - I was caught unexpected after someone at work couldn’t connect two to theirs.

Yes it was? It's literally on the tech specs page and was widely reported:

> Video Support

> Simultaneously supports full native resolution on the built-in display at millions of colors and:

> One external display with up to 6K resolution at 60Hz

https://www.apple.com/macbook-air/specs/

Re: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

#130

Post by akelly »

mmastrac wrote: post #116

I find it amusing that every single one of our high-speed standards (ethernet, HDMI, PCIE, displayport, USB) are basically just the same high-speed differential pairs under the hood with different framing. I don't know exactly what we can do about this situation, but at some point it probably makes sense for all of them to converge into a multi-lane, differential-pair standard (or just support nesting each other arbi…

Maybe we can call it a Universal Serial Bus
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