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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

#161

Post by wlesieutre »

sambroner wrote: post #130
wlesieutre wrote: post #104

Earlier quoted context omitted.

All ports on Apple's laptops behave the same for charging - they'll continue to provide power while sleeping, but won't start providing power. If you want to use it as a battery in your backpack while it's closed you have to plug your phone in, wake the computer up, then put it back to sleep. At least that was the case last time I tested it. For the most part they don't need colors because all of the ports are the sa…

Wow, "only starts charging while awake" really explains some confusing mornings waking up to a dead laptop.

To clarify, I'm talking about using the laptop as a power source to charge other devices (phones, tablets, etc) off your laptop's USB ports.

If you plug them in while the laptop is asleep they won't start charging. If you plug them in while the laptop is awake they'll start to charge, and they'll keep going if the computer goes to sleep later.

If you laptop isn't charging itself while plugged in to the wall you have other problems.

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

#162

Post by Retric »

cesarb wrote: post #157
elagost wrote: post #144

Earlier quoted context omitted.

I very much agree with you. I've deliberately avoided USB-C for this very reason. It's not that hard - I don't buy new gear very often, and I'm still using an old 5th-gen iPod every day - but there will be a day when I don't have much of a choice anymore. Bluetooth headphones, external hard drives, game controllers, media players, phones... The worst part about USB-C is that it can be implemented so wrong it bricks y…

> The worst part about USB-C is that it can be implemented so wrong it bricks your device! The miswiring that bricked his device, swapping GND and VBUS, could also happen with older USB plugs. There's nothing specific to USB-C about it, USB plugs have a defined polarity for the power pins since the very first version of the standard.

USB-C can send significantly more power, which makes it harder to protect devices in these cases.

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

#163

Post by tuscen »

gambiting wrote: post #139
colejohnson66 wrote: post #136

Earlier quoted context omitted.

Not true. See their thunderbolt cables: https://www.apple.com/shop/product/MD861LL/A/apple-thunderbo...

Fair enough. But their USB-C cables and chargers do not: https://www.apple.com/uk/shop/product/MLL82ZM/A/usb-c-charge...

That's because it's a USB Type-C cable that can handle only USB protocol. Thunderbolt 3 ones do have a logo on them [1].

Though, I do agree, having clear information directly on a USB Type-C cable on which features are supported would be much appreciated.

[1] https://www.apple.com/shop/product/MQ4H2AM/A/thunderbolt-3-u...

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

#164

Post by edwintorok »

gumby wrote: post #90
koala_man wrote: post #27

tl;dr: Intel made Thunderbolt 3 royalty free in 2018, so now it's essentially being adopted as USB4. I had to look up what the point of 40Gbps was, and the industry evangelization site https://thunderbolttechnology.net/ explains that it will allow driving one 5k display or two 4k displays, which is not possible with the 20Gbps offered by USB 3.2 or Thunderbolt 2. This also helps external GPUs, where TB2/USB3.2 is the…

Thunderbolt is PCIe so instead of a backplane you can use a cable. So basically anything you'd use PCIe for (drives, external GPUs etc) you can use TB for.

I'd be wary of plugging thunderbolt devices in, see http://thunderclap.io/

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

#165

Post by metaphor »

gumby wrote: post #59
artiscode wrote: post #46

Honestly, I'm waiting for old USB(USB A, USB B) to be deprecated and USB C become the new universal USB. As in ATM machine, you get the drill. Current USB cable situation is a mess - my phone is USB C, but it came with a USB A to USB C cable. Good thing I can connect it to my 2017 MacbookPro using it's original USB C charging cable! However then I can't charge. Sometimes I use a USB C to female USB A dongle to use my…

> good USB C cables seem to be made out of gold USB type C cables are active (they have silicon in them and handshake themselves with the host rather than simply being wire (possibly plus a resistor) as with old USB cables.) Cost will come down as volume goes up. Currently the only way to buy a cheaper cable is to buy a noncompliant and possibly dangerous one. > Life would become so much easier if everything was USB…

> Cost will come down as volume goes up.

I have no doubt overall cost will go down, but I'm curious by how much can we reasonably expect, and if said difference is actually meaningful.

Consider Type-C qualification testing[1] as it stands...it's quite convoluted. Any cost savings from volume economies of scale would be all for nought if testing such high-performance products can't scale proportionally. Given Type-C was specifically designed for the cost sensitive consumer market from the onset and how capability keeps increasing in ways that make one wonder if it's even the same fundamental underlying technology anymore, I wonder how close to the "market noise floor" a qualified device truly is.

In the defense/aerospace industry, it's commonplace for a $0.07 electronic component to have $10 of testing behind it before profit and indirect costs are baked in. Same outcome with MIL-DTL-38999 interconnect, which has literally been around for longer than I've been alive, supplied by multiple competing manufacturers, and leveraged by multiple industries (not just mil/aero)--testing requirements ultimately keep costs high. Although not the mil/aero market, it wouldn't surprise me if Type-C is already close to a similar point of diminishing returns.

[1] https://www.usb.org/usbc

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

#166

Post by sjwright »

colejohnson66 wrote: post #136
gambiting wrote: post #125

Earlier quoted context omitted.

Apple cables and ports have no logos on them whatsoever. Just plain white/silver if metal.

Not true. See their thunderbolt cables: https://www.apple.com/shop/product/MD861LL/A/apple-thunderbo...

That's not a USB-C cable.

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

#167

Post by NullPrefix »

starpilot wrote: post #40
randyrand wrote: post #13

Earlier quoted context omitted.

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.

Why not turn them on all at once?

Crosstalk with other pairs.

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

#168

Post by nickysielicki »

Retric wrote: post #162
cesarb wrote: post #157

Earlier quoted context omitted.

> The worst part about USB-C is that it can be implemented so wrong it bricks your device! The miswiring that bricked his device, swapping GND and VBUS, could also happen with older USB plugs. There's nothing specific to USB-C about it, USB plugs have a defined polarity for the power pins since the very first version of the standard.

USB-C can send significantly more power, which makes it harder to protect devices in these cases.

It only happens after negotiation, so the higher potential wattage plays no role here. You'd need both a bad cable and an out-of-spec wall wart.

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

#170

Post by Dylan16807 »

kondro wrote: post #156
Dylan16807 wrote: post #103

Earlier quoted context omitted.

Not 'just' at all. USB 2 has a single twisted wire pair, specced for moderate speed. USB 3 replaces that with two pairs with much tighter requirements, one for transmit and one for receive. This involves a tenfold speed boost (.5Gbps to 5Gbps), with much more modern transceivers using much higher frequencies on much better wires. But it also drops the length a single passive cable can be from about 5 to 2 meters. USB…

Now, if only someone would actually ship a USB-C 3.2 (or Thunderbolt) active cable. :( I have a couple of situations I would like a 7m-ish Thunderbolt 3 cable but can’t seem to find one, even for the multiple-hundreds it would probably cost.

Corning has several lengths of optical thunderbolt 2 cable, do you need it to be thunderbolt 3 specifically?
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