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USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

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Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#251

Post by Mirioron »

notJim wrote: post #159
modeless wrote: post #73

Is it an unpopular opinion that USB is already fast enough and has enough features and USB implementers should instead work on cost reduction and compatibility so that we can all move away from USB 2 and pre-type-C connectors?

It's not fast enough. USB cannot drive a 4k monitor at 60hz. You can use the physical interface to do it, but this uses Thunderbolt. This means that the dream of a one-cable-for-everything setup is not here yet, unless you use a Thunderbolt dock, which multiplexes the USB stuff in with the monitor signal. A thunderbolt dock costs around 10x more than a simple USB dock.

One cable for everything will mean that the cables cost an insane amount though.

Oh, and they will either be short or require power to run the cable itself.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#252

Post by coldtea »

Mirioron wrote: post #245
coldtea wrote: post #242

Earlier quoted context omitted.

> No one is going to build a USB mouse with a 40Gbit link speed, for example. No, but they could build cables with a "40Gbit link speed" that also work with any much smaller speed mouse. Devices don't have to have the superset. But if a consumer wants to buy a cable that has the superset of powers, they should be able to find such cables and buy them.

Is that true though? Usually throughput comes at the cost of latency. Is that not the case with USB cables?

That's when the full throughput is utilized though. Why couldn't it have "modes" depending on the latency needs of the device?

(Plus, what low throughput device has low latency needs that can't be covered by cable able to push data to a 4K monitor at 120 hz or more)

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#253

Post by gambiting »

sneak wrote: post #225
mjevans wrote: post #142

Earlier quoted context omitted.

Pick any random USB-C cable. Can you tell by looking at it what speeds it supports? Is it USB-3 or USB-2? How about the power delivery aspect, how much power is it cable of transferring? You might be able to tell some of those things from modern cables, if they're bragging about a speed factor, but otherwise it isn't clear.

Pick any random cable, regardless of what’s on the ends. Yes, I can determine what it is used for, because I bought it for a purpose. What you are describing is the same issue with barrel-style AC or DC wall warts, and those powered the world for a few decades just fine.

Except that as I said in another comment - the USB-C charger that comes with OnePlus phones will not charge the Nintendo Switch. Both devices have full USB-C certification and display USB Association logo on the box. But it's either OnePlus or Nintendo doing something dodgy with the standard and the Switch just doesn't charge.

So yes, I bought a USB-C certified charger, to charge things. What does it do? It charges some things when it wants to, without providing any kind of indication why it doesn't work when it doesn't.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#254

Post by projektfu »

_wmd wrote: post #57
chrisseaton wrote: post #48

Earlier quoted context omitted.

> With USB 3.0 they added 4 more signals for separate transmit/receive So is it not actually serial any more?

Transmit and receive previously shared pins, USB 3 split transmit and receive into separate pairs, which are still serial edit: yikes, looks like USB C doubled the number of those separate pairs, for a total of 6 data pins (2x RX, 2x TX, 2x USB 2.0 RX/TX)

It’s better to say they were mirrored to make the connector work the same upside down, and then they expanded the spec to allow simultaneous use, effectively doubling the throughput.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#255

Post by WhitneyLand »

johncolanduoni wrote: post #226
WhitneyLand wrote: post #210

Earlier quoted context omitted.

Not sure you're countering my argument at all because I of course agree we can't just blindly do things that make systems impractical to buy or use. If fact I would certainly be all for a few basic well thought out combinations as mentioned: >> one thing with nothing optional (or at least a very small number of combinations) The problem is, that's not what USB-C/USB-3 whatever is. It's permutations must be in the mil…

What are the degrees of freedom in the spec that are resulting in millions of permutations of optional features?

In addition to what RHN said, you've got to count absence of some of those features as another combination so you've got whatever power limits there are and also no power.

You've also got cable lengths which I don't believe are limited by the spec but technologically limited. For example you can by 10 foot cables on Amazon but I believe it's currently impossible to buy any 10 foot cable there that has all the features supported that the spec allows for.

Effectively this adds just as much complexity as something formally defined as a feature because end users have to deal with the additional variables just the same.

I'm really trying to avoid doing enough research and combinatorics that would allow for an exact number but look, we're already at thousands which is ridiculous and you know how quickly the numbers grow with only a handful of additional headaches added in.

We're also not counting edge cases like Apples Adapters that are supposed to allow an iOS device to charge while using USB accessories. That's another niche batch of secrets introduced with the 2018 iPad Pros. It only charges using certain combinations not simple requirements like having enough power.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#256

Post by mnx »

majewsky wrote: post #233
WhitneyLand wrote: post #124

What's optional? That's the most important thing to know is what's optional in the spec. That could make it great or a major pain. I'm referring to how many features the specification defines as "optional" for manufactures and that the USB organization requires for logos. This is why even USB-C is a nightmare. Consider a USB-C cable or device port. It could be charge only, data only, monitor support. There are even m…

Market opportunity: A USB-stick-shaped device that, when you plug it into a USB-C port, probes the port and lights up LEDs to show the port's capabilities. [x] 5 Gbps [x] 10 Gbps [ ] 20 Gbps [ ] Power Delivery [x] DisplayPort Alternate Mode And so on.

Yeah until the spec changes/expands and you now need another device to tell you whether that stick is up-to-date on the spec :D

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#257

Post by redcalx »

majewsky wrote: post #233
WhitneyLand wrote: post #124

What's optional? That's the most important thing to know is what's optional in the spec. That could make it great or a major pain. I'm referring to how many features the specification defines as "optional" for manufactures and that the USB organization requires for logos. This is why even USB-C is a nightmare. Consider a USB-C cable or device port. It could be charge only, data only, monitor support. There are even m…

Market opportunity: A USB-stick-shaped device that, when you plug it into a USB-C port, probes the port and lights up LEDs to show the port's capabilities. [x] 5 Gbps [x] 10 Gbps [ ] 20 Gbps [ ] Power Delivery [x] DisplayPort Alternate Mode And so on.

Also how any watts of power delivery. From observation it seems to vary.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#258

Post by fendy3002 »

coldtea wrote: post #239
WhitneyLand wrote: post #124

What's optional? That's the most important thing to know is what's optional in the spec. That could make it great or a major pain. I'm referring to how many features the specification defines as "optional" for manufactures and that the USB organization requires for logos. This is why even USB-C is a nightmare. Consider a USB-C cable or device port. It could be charge only, data only, monitor support. There are even m…

> This is why even USB-C is a nightmare. Consider a USB-C cable or device port. It could be charge only, data only, monitor support. There are even more permutations and sub-features. Oh, you wanted charging and found one that has it? Know how much power it enough or overkill? It could provide 15 watts, 100 watt, etc. Think you'll just google the specs page? Sure, they never miss providing any of these details or mak…

Or like the good ol rca cables: color, or . Add some stripes in the head of usb or similar and add some stripes with meaningful color.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#259

Post by Yetanfou »

mnx wrote: post #256
majewsky wrote: post #233

Earlier quoted context omitted.

Market opportunity: A USB-stick-shaped device that, when you plug it into a USB-C port, probes the port and lights up LEDs to show the port's capabilities. [x] 5 Gbps [x] 10 Gbps [ ] 20 Gbps [ ] Power Delivery [x] DisplayPort Alternate Mode And so on.

Yeah until the spec changes/expands and you now need another device to tell you whether that stick is up-to-date on the spec :D

As long as the actual port remains identical the widget could be made up to date with a software upgrade.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#260

Post by raducu »

Yetanfou wrote: post #259
mnx wrote: post #256

Earlier quoted context omitted.

Yeah until the spec changes/expands and you now need another device to tell you whether that stick is up-to-date on the spec :D

As long as the actual port remains identical the widget could be made up to date with a software upgrade.

You cannot add a led with a software update :)
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