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USB Cheat Sheet (2022)

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Re: USB Cheat Sheet (2022)

#21

Post by xzjis »

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…

Or it could be: 5 Gbps --> USB 3 10 Gbps --> USB 3.1 20 Gbps --> USB 3.2

Higher number = better

Re: USB Cheat Sheet (2022)

#22

Post by syhol »

brcmthrowaway wrote: post #2

Where does TB5 come into all of this?

- Thunderbolt 3 is a superset of USB 3.1

- USB4 is built on Thunderbolt 3's protocol, implementing a subset of its mandatory features

- Thunderbolt 4 is a strict profile of USB4 (all optional features made mandatory)

- USB4 v2 introduced 80 Gbps signaling

- Thunderbolt 5 is a strict profile of USB4 v2 (again, optional features made mandatory)

Re: USB Cheat Sheet (2022)

#23

Post by retired »

The simplicity of Thunderbolt. Versions 1 and 2 used mini DisplayPort, 3 and upwards USB-C. Version 1 was 10Gbps, 2 was 20Gbps, 3 was 40Gbps, 4 was 40Gbps, 5 is 80 or 120Gbps with boosting.

A Thunderbolt 5 cable will always support 80Gbps, DisplayPort 2.1, PCIe, USB4 and power of up to 240 watt.

Re: USB Cheat Sheet (2022)

#24

Post by conception »

This article is why I replaced all the usb dock cables in the office to make sure the usb cable connected to the laptops was transferring enough power so the laptop wouldn't silently lower its frequency for the lower power draw. 10-30% speed bump just because.

Re: USB Cheat Sheet (2022)

#26

Post by retired »

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.

And not only the sales people. Windows doesn't report anywhere what your motherboard is capable of, and even if you connect with a device it will not tell you the speed it agreed on.

Re: USB Cheat Sheet (2022)

#27

Post by DiabloD3 »

stevex wrote: post #9
Neywiny wrote: post #6

Earlier quoted context omitted.

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

Doesn't it run over a USB-C shaped wire? If you're trying to understand things that plug into USB-shaped ports it seems at least worth mentioning.

To be fair: You should refer to these as Type-C cables, as they carry things that are not USB protocol.

The sole exception should be made for "charge only" cables, which can, and should, be referred to as "wired for USB 2.0". These cables "shouldn't" exist, but I also don't want to buy a $30 cable just to charge my phone.

Re: USB Cheat Sheet (2022)

#28

Post by mistyvales »

kimixa wrote: post #17
mistyvales wrote: post #8

Earlier quoted context omitted.

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.

Manufacturers of mainstream consumer motherboards never used 1.1, 2.1, etc. for PCI-E though. What is 4.0 on the spec sheet will be 4.0 to the buyer. My old 2016 motherboard has a slew of 3.0 labelled USB ports that are now not 3.0, hence the conundrum. It just doesn't make sense why they changed established naming conventions. Is this something that causes me sleepless nights? Not in the least. But it's still an annoyance for consumers and even advanced users as detailed in that latest Geerling video et al.

Re: USB Cheat Sheet (2022)

#29

Post by retired »

mschuster91 wrote: post #4
15155 wrote: post #3

Good sheet. Worth adding: - Female vs male crossover naming and pinouts for Type-C connectors - Actual voltage, modulation and signaling schemes (USB4v2 uses PAM3 11b/7t encoding) - PD generations and profiles

... and the bunch of proprietary voltage schemes like Quickcharge.

Thanks to the EU those are now forbidden, all phones and laptops should be compatible with USB-PD.

Update: USB-PD is a requirement, but manufacturers are allowed to have their own proprietary charging solution.

Re: USB Cheat Sheet (2022)

#30

Post by pxeboot »

I still don't understand why MacBooks support USB4/Thunderbolt 4/5, but NOT USB 3.2 Gen 2x2. So you can get 20-40Gb/s speeds with more expensive external disks, but only 10Gb/s with the cheaper, more commonly available ones that advertise 20Gb/s.
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