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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

#241

Post by rhn_mk1 »

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?

Not millions, but:

- Power Delivery supports some 5 different maximum values

- 3 different Battery Charging modes

- 5 alternate modes according to Wikipedia (C only)

- >10 different plugs (not an independent variable though)

- 6 different signalling rates

All of those are baked in in the hardware layer. It gets worse when you realize that cables have to support the right combination.

It gets even worse when including things that piggyback on USB, like dual-purpose HDMI and USB ports, Thunderbolt, noncompliant chargers (Apple), Quick Charge, audio alternate mode.

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

#242

Post by coldtea »

userbinator wrote: post #177
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…

The only way you can make a specification like USB "universal" is for parts of it to be optional. No one is going to build a USB mouse with a 40Gbit link speed, for example.

>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.

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

#243

Post by coldtea »

p1mrx wrote: post #220
userbinator wrote: post #177

Earlier quoted context omitted.

The only way you can make a specification like USB "universal" is for parts of it to be optional. No one is going to build a USB mouse with a 40Gbit link speed, for example.

What if it's a high DPI gaming mouse?

Even then it could make do with much much much slower rates -- those are monitor rates, and we're talking about a mouse here (hi dpi or not).

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

#244

Post by Mirioron »

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…

Why is USB-C like that? Is it because all smartphones require USB chargers in the EU and so everything that manufacturers might want has to be in the one cable spec?

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

#245

Post by Mirioron »

coldtea wrote: post #242
userbinator wrote: post #177

Earlier quoted context omitted.

The only way you can make a specification like USB "universal" is for parts of it to be optional. No one is going to build a USB mouse with a 40Gbit link speed, for example.

> 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?

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

#246

Post by Mirioron »

bryanlarsen wrote: post #119
gambiting wrote: post #100

Earlier quoted context omitted.

So remind me, why can you walk into any apple store, pick up a new MacBook and a 5K LG monitor, and when you plug in the monitor using the USB-C cable that was bundled with the MacBook it just won't work at all? My point is - the standards might be back and forward compatible. But the cables and ports definitely aren't - and your average consumer has absolutely no way of knowing. They look absolutely identical on the…

There are two problems: 1. the same connector is used for a wide variety of capabilities, and it can get confusing knowing what you can use together. 2. the names of these connectors is confusing. You're complaining about the first, and that's a very hard problem. There are huge advantages to using the same connector and cables that can support 100W of power, 5K displays and also support peripherals that retail for l…

>There are huge advantages to using the same connector and cables that can support 100W of power, 5K displays and also support peripherals that retail for less than $1 and be backwards compatible with peripherals over 20 years old.

This, quite honestly, sounds wasteful. I am fairly certain that manufacturing these connectors that are much better is more expensive than either the old, less sophisticated, connectors or simply new lower performance connectors.

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

#247

Post by xxs »

randyrand wrote: post #13
davnicwil wrote: post #6

As someone who knows next to nothing about how USB actually works and just uses it, what goes into making each USB generation faster? At the physical layer, is it the materials in the cables are getting better? Or new ways of using the same materials? At the protocol layer, is it newly developed computer science theory being applied or is it just old fashioned pragmatic engineering iteration, looking at usage and mak…

Nope. Much simpler. Just enabling the use of the other data lanes that were already in the cable waiting to be used one day. USB-C has 4 differential twisted pair data lines.

I still wonder why the 'S' in the name - USB has stopped being serial (or bus) for quite some time.

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

#248

Post by asafira »

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.

Even better if it is actually a usb stick, too.

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

#250

Post by makomk »

protomyth wrote: post #203
abrowne wrote: post #199

Earlier quoted context omitted.

Yes, if you buy it standalone. But what about in the computer box? I've opened a lot of MacBook Pros, and I can't remember seeing any labeling.

I’ve gotten into the habit of taking the supplied cable on all Mac portables and replacing it with a Thunderbolt 3 40gbs 100w cable from Monoprice before handing it over to the staff person. It cuts down on “why won’t this work” questions surrounding monitors and such.

Except that longer Thunderbolt 3 cables apparently don't support 10 GBps USB 3.1 speeds. So if you want a cable that actually supports everything, it probably has to be the 0.5m Thunderbolt 3 40gbs 100w cable from Monoprice (maybe the 1m one too, but the 2m version is an active cable that won't support USB 3.1)
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