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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

#101

Post by cm2187 »

gumby wrote: post #96
cm2187 wrote: post #88

I'd be curious about 40Gbps for what cable length. TB3 is great, you can in theory dock a laptop with a single cable that will do charging, 10gbe, USB hub, etc, but with a max 50cm cable, which makes it quite "un-lappable". I'd love to do the same with a 2m cable.

Copper thunderbolt limit is 3 m. Optical thunderbolt can go much farther (naturally) but I've never seen it in the wild -- it might even have been abandoned by now.

But you can't charge a laptop with an optical cable. As for copper, I understand you don't get 40gbps with a 3m cable (though not a specialist).

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

#102

Post by woolvalley »

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.

Not quite, because the equivalent pure pcie connection is faster than thunderbolt due to the overhead in thunderbolt.

We need another doubling in thunderbolt's speed for it to not have a penalty when using eGPUs

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

#103

Post by Dylan16807 »

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.

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 C doubled the number of pins while making the plug reversible, so they went ahead and made the special case of C-to-C cables connect to all the pins and have four pairs of wires.

But that's only a doubling from 5Gbps to 10Gbps. How are we getting up to 20 or 40? It's mostly coming from restricting cable length even further, down to 1 meter or only half a meter. But on the bright side you can get an active cable, with chips inside, that can get you back up to 1 meter or 2 meters or 60 meters. As long as you're willing to pay enough.

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

#104

Post by wlesieutre »

jsgo wrote: post #99
DaiPlusPlus wrote: post #64

Earlier quoted context omitted.

Apple will never use coloured ports.

pulling my MacBook Pro out of my backpack to look, it looks like they aren't fans of iconography to say what a port is capable of either. Can't remember if my old 2013 MBP had the icons or not, but my current one for sure doesn't.

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 same. One recent exception was that the 2016/2017 MBPs had inconsistent Thunderbolt bandwidth because they didn't have enough PCIe lanes. IIRC left side had full 40Gbps ports but the right side had 20Gbps. The 2018 version has full speed on all four.

EDIT - another potential point of confusion, they don't mark Thunderbolt ports vs USB-C ports. On any given device they're all the same, but they expect you to know that the 12"-mini-macbook is just USB-C while the Pro and Air are all Thunderbolt.

So yeah, it'd be helpful to have some symbols on the laptops. They do label ports on their desktops. I assume this comes down to Ive not wanting labels on his beautiful chunk of aluminum where someone might accidentally see them while using it.

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

#105

Post by jsgo »

wlesieutre wrote: post #52
walterbell wrote: post #25

Earlier quoted context omitted.

we use yellow for power/charging

Yellow IIRC means "provides power even when the computer is sleeping." It'd be harder to do markings like this on USB-C ports though. They don't have a big visible chunk of plastic in the middle.

I was being a bit facetious with the initial suggestion, honestly. Mostly poking at color being used as a universal indicator, and then you have a case like Razer where they introduce green to be complementary to their laptop's color scheme.

Beyond just switching to brand + version number (ie [USB logo] 4, [thunderbolt logo] 3, etc.), I don't know of a great way to really go about this. Otherwise you end up with the super speed championship edition thing you posted, which isn't going to help anyone really.

I think the color one was a great idea on their part in that you didn't have to look too close to see which port you were plugging into, but all it takes is one detractor to deviate from it (say if MSI came out with a gaming laptop with red USB2 ports), and then the whole idea is shot.

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

#106

Post by benj111 »

izacus wrote: post #86
sp332 wrote: post #3

Ars Technica just wrote an article about the confusing names of USB versions https://arstechnica.com/gadgets/2019/02/usb-3-2-is-going-to-... and now they have another one about this name. https://arstechnica.com/gadgets/2019/03/thunderbolt-3-become...

I feel like hand-wringing around that is a bit overexaggerated - at the end of the day the differences really matter for only really tiny subset of devices that need those 10GBit+ transfers and in that case you can guide yourself by the "SuperSpeed 10Gbit" "Superspeed 20Gbit" logos on the actual box. For everything else the protocols are forward and backward compatible, so you just plug in the cable and it works.

That sounds like '10Gbit ought to be more than enough for anybody' to me.

Plus the good thing about USB is it just works, you don't have to worry about any tiny subset (well that's the theory anyway).

I've had enough of my monitor, mouse, keyboard and printer all using different connectors thank you very much.

Edit: Making make sense.

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

#107

Post by p1esk »

izacus wrote: post #89
p1esk wrote: post #84

Earlier quoted context omitted.

Is it fast enough for 4K120 or 8k displays?

USB or the alternate modes over USB-C connector?

The modes don't matter if bandwidth is not there.

Ultimately, I just want every monitor and TV to support a single universal interface, fast enough for the highest resolution/refresh rate. I don't care how it's called or how it works. If "USB 4.0" can be it, great.

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

#108

Post by zanny »

bubblethink wrote: post #91
gigatexal wrote: post #23

Royalty free is the huge boon here.

Intel said that a couple of years ago, and yet you won't find an AMD laptop/desktop that supports thunderbolt.

One, what AMD laptop?

Two, I'd be interested to know if AMD bans board manufacturers from including TB or if they just don't do it because their heuristics say users don't care or want it.

I'd imagine now with the rise of USB-C it would be the latter. Before that AMD was stuck on a 5 year old desktop platform that probably couldn't run thunderbolt ports even if board makers wanted to include it.

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

#109

Post by pariahHN »

jwr wrote: post #61
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…

Don't get your hopes up, as this is just a dream. USB-C only specifies the connector. What your cables support, and what end devices support is anyone's guess. See for example https://superuser.com/questions/1199917/what-is-the-d-shaped... In my opinion, the mess is actually much worse with USB-C, as with earlier connectors I at least had a chance of guessing whether the cable/connection will work by looking at the c…

It's not like we already had a cable and protocol that could encapsulate arbitrary data and transmit it between devices without concern for what upper level protocols were in use or what the data type was, with the only concern with regards to the cable being the max speed supported.

Oh, wait, Ethernet is a thing. I wonder how they just completely missed that when making USB 3. The only thing that should be differentiated between cables is max power delivery rating and data rate.

Edit: typo

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

#110

Post by bazooka_penguin »

gambiting wrote: post #100
izacus wrote: post #86

Earlier quoted context omitted.

I feel like hand-wringing around that is a bit overexaggerated - at the end of the day the differences really matter for only really tiny subset of devices that need those 10GBit+ transfers and in that case you can guide yourself by the "SuperSpeed 10Gbit" "Superspeed 20Gbit" logos on the actual box. For everything else the protocols are forward and backward compatible, so you just plug in the cable and it works.

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…

The cables should have a ss or ss 10 or ss 20 label on them. The end devices should too I believe.
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