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USB Cheat Sheet (2022)

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Re: USB Cheat Sheet (2022)

#11

Post by maxloh »

I once heard that the USB naming is misleading by design so that vendors could still sell older generations accessories they had in stock. The USB-IF just rebrands the old ones to make them sound current.

Imagine the following naming:

  USB 3.0 / USB 3.1 Gen 1 / USB 3.2 Gen 1 -> USB 3 5Gbps
  USB 3.1 / USB 3.1 Gen 2 / USB 3.2 Gen 2 -> USB 3 10Gbps
  USB 3.2 Gen 2x2 -> USB 3 20Gbps
Isn't that much clearer? I think USB 4 is finally going to the right direction.

Re: USB Cheat Sheet (2022)

#12

Post by aleph_minus_one »

Neywiny wrote: post #6
brcmthrowaway wrote: post #2

Where does TB5 come into all of this?

I don't see why it would. Thunderbolt is not a USB standard

> Thunderbolt is not a USB standard

Concerning Thunderbolt 3: USB4 is based on the Thunderbolt 3 protocol [1].

Concerning Thunderbolt 4: "In July 2020 Intel announced Thunderbolt 4 as an implementation of USB4 40 Gbit/s with additional requirements, such as mandatory backward compatibility to Thunderbolt 3 and requirement for smaller notebooks to support being charged over Thunderbolt 4 ports.[14] Publications such as AnandTech described Thunderbolt 4 as "superset of TB3 and USB4" and "able to accept TB4, TB3, USB4, and USB 3/2/1 connections"." [2]

Concerning Thunderbolt 5: Intel considers Thunderbolt 5 as an implementation of USB4 Version 2.0. [3]

[1] https://en.wikipedia.org/w/index.php?title=USB4&oldid=134742...

[2] https://en.wikipedia.org/w/index.php?title=USB4&oldid=134742...

[3] https://en.wikipedia.org/w/index.php?title=USB4&oldid=134742...

Re: USB Cheat Sheet (2022)

#13

Post by aleph_minus_one »

Kirby64 wrote: post #7
Neywiny wrote: post #6

Earlier quoted context omitted.

I don't see why it would. Thunderbolt is not a USB standard

Thunderbolt 5 and USB4v2 are the same thing now. They both support 80gbps and pcie pass through.

> Thunderbolt 5 and USB4v2 are the same thing now. They both support 80gbps and pcie pass through.

Not completely true: Thunderbolt 5 demands some capabilities that are optional for USB4v2.

Re: USB Cheat Sheet (2022)

#14

Post by stackghost »

brcmthrowaway wrote: post #2

Where does TB5 come into all of this?

Thunderbolt 5 is basically just PCI Express, power delivery, and DisplayPort over the same cable, which for reasons passing understanding is terminated with a USB-C connector.

I think most of those cables will also support USB the protocol.

Re: USB Cheat Sheet (2022)

#16

Post by Neywiny »

mistyvales wrote: post #8
Neywiny wrote: post #5

I actually like the 3.2 naming. Gen is speed, "by" is width. It puts it very roughly on par with PCIe's naming which nobody complains about. I just don't like that USB 3, USB 3.1, and USB 3.2 are the same things. And that sales people don't seem to understand that saying a chip supports 3.1 or 3.2 tells me it's anywhere from 5-20gbps which isn't ideal.

PCI-E has had the same standard since its inception: 1.0, 2.0, 3.0, etc. USB has changed multiple times and has remained confusing for the vast majority of people. What was 3.0 is now not 3.0. Even 3.1 has changed. There is no reason to use this naming convention they currently have but for some reason they stick with it..

Possibly they stick with it because it's usable (ish) and it was driving everyone up the wall when they'd change it?

Re: USB Cheat Sheet (2022)

#17

Post by kimixa »

mistyvales wrote: post #8
Neywiny wrote: post #5

I actually like the 3.2 naming. Gen is speed, "by" is width. It puts it very roughly on par with PCIe's naming which nobody complains about. I just don't like that USB 3, USB 3.1, and USB 3.2 are the same things. And that sales people don't seem to understand that saying a chip supports 3.1 or 3.2 tells me it's anywhere from 5-20gbps which isn't ideal.

PCI-E has had the same standard since its inception: 1.0, 2.0, 3.0, etc. USB has changed multiple times and has remained confusing for the vast majority of people. What was 3.0 is now not 3.0. Even 3.1 has changed. There is no reason to use this naming convention they currently have but for some reason they stick with it..

PCIe also had things like "1.1", "2.1" and "3.1" - that fixed issues and added functionality - but there wasn't the same crossover between "feature sets and spec revisions" and "speeds" we see in USB today.

Re: USB Cheat Sheet (2022)

#18

Post by kubik369 »

maxloh wrote: post #11

I once heard that the USB naming is misleading by design so that vendors could still sell older generations accessories they had in stock. The USB-IF just rebrands the old ones to make them sound current. Imagine the following naming: USB 3.0 / USB 3.1 Gen 1 / USB 3.2 Gen 1 -> USB 3 5Gbps USB 3.1 / USB 3.1 Gen 2 / USB 3.2 Gen 2 -> USB 3 10Gbps USB 3.2 Gen 2x2 -> USB 3 20Gbps Isn't that much clearer? I think USB 4 is…

I think this practice is rather blatantly what you say. The same thing with HDMI forum folding HDMI 2.0 into HDMI 2.1. They made the new 2.1 features optional, therefore manufacturers were able to call their 2.0 devices 2.1 without actually supporting the 2.1 features. AMD has been recently doing similar things, releasing “new” generation of mobile processors where half of them are just rebrands of the older generation.

Re: USB Cheat Sheet (2022)

#19

Post by Kirby64 »

aleph_minus_one wrote: post #13
Kirby64 wrote: post #7

Earlier quoted context omitted.

Thunderbolt 5 and USB4v2 are the same thing now. They both support 80gbps and pcie pass through.

> Thunderbolt 5 and USB4v2 are the same thing now. They both support 80gbps and pcie pass through. Not completely true: Thunderbolt 5 demands some capabilities that are optional for USB4v2.

From a protocol/bandwidth level, it’s essentially the same though. Thunderbolt 5 has some more guarantees for power and display, but the data rate of the two is the same.
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