I have been shopping for an external hard drive, and encountered confusing descriptions about what USB ports are on the device.
This article cleared it up, but it is still very complicated.
https://www.tomshardware.com/news/usb-31-usb-type-c-refresher,29933.html
A few excerpts:
Quote
...over the last year or so, there have been many developments in the USB space, and although the official specifications haven't changed, we've consolidated and explained all the helpful information around USB 3.0, both versions of USB 3.1, and the USB Type-C connector........we spoke at length with the USB Implementer's Forum (USB-IF) to craft a primer, if you will, about all things USB and Type-C.
...There are two types of USB 3.1: There's a Gen1 and a Gen2, and they offer different data transfer speeds. Both USB 3.0 and USB 3.1 Gen1 can transfer data at speeds up to 5.0 Gbps (8b/10b encoding), whereas USB 3.1 Gen2 can transfer data at speeds up to 10 Gbps (128b/132b encoding).
USB 3.0 and USB 3.1 Gen1 are actually the same thing -- almost. Simply put, USB 3.1 Gen1 is USB 3.0 plus all of the changes that have been made to USB 3.0 over the years. According to the USB-IF's documents, these changes include "added performance boosts to meet requirements for USB storage, display and docking applications," as well as USB 3.0 Engineering Change Notices (ECNs).
...You may have never even seen an OEM specify "Gen1" or "Gen2" in marketing materials mentioning USB 3.1. Partially, this is because the USB-IF uses specific branding to clarify which USB 3.1 is which. USB 3.1 Rev1 (5 Gbps) is called "SuperSpeed USB," and USB 3.1 Rev2 (10 Gbps) is called "SuperSpeed USB 10 Gbps." Note that on the actual logos, these appear as "SuperSpeed" and "SuperSpeed+," respectively. (What's in a "+" sign? Double the data speed, that's what.)
...not only are there multiple versions of USB 3.1 that require clarification, USB Type-C is a much more flexible connector (pun not intended) than older USB standards, and USB PD is another wildcard; in other words, the mere presence of a Type-C port on a device tells you little about what that particular port can do.
...As we mentioned, "USB Type-C" doesn't mean "USB 3.1." Although many -- possibly, most -- applications of USB Type-C will involve USB (one "Gen" or the other), the USB Type-C port design allows for additional features...........For starters, there is USB Power Delivery, which is a feature that allows devices to deliver up to 100 W of power through a USB port...........Additionally, USB Type-C can support DisplayPort as an Alternate Mode, as well as MHL and Thunderbolt 3 (with Intel's new Alpine Ridge controller). Theoretically, one could route just about any protocol through USB Type-C.
...One USB Type-C cable won't be identical to another, which means consumers will have to be careful when buying one, paying close attention to a given cable's capabilities
This article cleared it up, but it is still very complicated.
https://www.tomshardware.com/news/usb-31-usb-type-c-refresher,29933.html
A few excerpts:
Quote
...over the last year or so, there have been many developments in the USB space, and although the official specifications haven't changed, we've consolidated and explained all the helpful information around USB 3.0, both versions of USB 3.1, and the USB Type-C connector........we spoke at length with the USB Implementer's Forum (USB-IF) to craft a primer, if you will, about all things USB and Type-C.
...There are two types of USB 3.1: There's a Gen1 and a Gen2, and they offer different data transfer speeds. Both USB 3.0 and USB 3.1 Gen1 can transfer data at speeds up to 5.0 Gbps (8b/10b encoding), whereas USB 3.1 Gen2 can transfer data at speeds up to 10 Gbps (128b/132b encoding).
USB 3.0 and USB 3.1 Gen1 are actually the same thing -- almost. Simply put, USB 3.1 Gen1 is USB 3.0 plus all of the changes that have been made to USB 3.0 over the years. According to the USB-IF's documents, these changes include "added performance boosts to meet requirements for USB storage, display and docking applications," as well as USB 3.0 Engineering Change Notices (ECNs).
...You may have never even seen an OEM specify "Gen1" or "Gen2" in marketing materials mentioning USB 3.1. Partially, this is because the USB-IF uses specific branding to clarify which USB 3.1 is which. USB 3.1 Rev1 (5 Gbps) is called "SuperSpeed USB," and USB 3.1 Rev2 (10 Gbps) is called "SuperSpeed USB 10 Gbps." Note that on the actual logos, these appear as "SuperSpeed" and "SuperSpeed+," respectively. (What's in a "+" sign? Double the data speed, that's what.)
...not only are there multiple versions of USB 3.1 that require clarification, USB Type-C is a much more flexible connector (pun not intended) than older USB standards, and USB PD is another wildcard; in other words, the mere presence of a Type-C port on a device tells you little about what that particular port can do.
...As we mentioned, "USB Type-C" doesn't mean "USB 3.1." Although many -- possibly, most -- applications of USB Type-C will involve USB (one "Gen" or the other), the USB Type-C port design allows for additional features...........For starters, there is USB Power Delivery, which is a feature that allows devices to deliver up to 100 W of power through a USB port...........Additionally, USB Type-C can support DisplayPort as an Alternate Mode, as well as MHL and Thunderbolt 3 (with Intel's new Alpine Ridge controller). Theoretically, one could route just about any protocol through USB Type-C.
...One USB Type-C cable won't be identical to another, which means consumers will have to be careful when buying one, paying close attention to a given cable's capabilities