The USB 3.0 standard was a major leap in quality over its predecessor, and we've been able to enjoy (almost) all of its improvements without sacrificing backward compatibility. But demands keep rising: faster drives, larger files, quick battery charging, and 8K on the horizon are more than enough reasons to adopt a superior standard. That role will fall to USB4, which first and foremost promises to double the available speed without changing the connector, so all our Type-C devices will work perfectly.
It barely stands out on our computers with a bit of blue plastic, or in the form of the "new" Type-C connector we can already find in dozens of mobile devices, including consoles like the Nintendo Switch. USB 3.0 (with its later revisions) has adapted without major incidents to our daily sessions, and we're sure it will accompany us for many more years. However, it's time to think about an upgrade.
Let's make room for USB4. Why "USB4"? According to the USB Promoter Group, the goal is to avoid the confusion generated by minor updates (3.0, 3.1, 3.2), and from a certain point of view, the improvements are big enough to justify a name change. Even so, the use of "USB4" hasn't been fully confirmed, so there's a possibility it will be called something else later.
USB4: Fast and Furious Compatible
So, what does USB 4 bring to the table? In a word, speed. While USB 3.2 offers a maximum of 20 gigabits per second (in the best case), USB4 will double that value, reaching a new ceiling of 40 gigabits per second. But that's not all: USB4 will allow some devices to switch the link from "bidirectional" to "unidirectional". The most relevant case will be DisplayPort 2.0's "Alt Mode", which under USB4 will work at an impressive 80 gigabits per second, ideal for 8K HDR, and even 16K is speculated. At the same time, that will enable certain USB4 devices to incorporate Thunderbolt 3 support (as long as the manufacturer decides to do so).
Another very interesting aspect of USB4 is its compatibility with USB Power Delivery. If a mobile device supports that same standard, charging times will be drastically reduced, although we should take this with a grain of salt. The certification and validation conflicts in Type-C USB chargers are well known, to the point that they've caused many headaches. USB4 needs to root out those difficulties at the source, or otherwise it will become an old problem with a new name.
To finish, USB4 guarantees backward compatibility. The available speeds between certified USB 4 devices will be 10, 20, and 40 Gbps (except for the aforementioned DisplayPort 2.0 Alt Mode), but by keeping the same connector, a USB4 cable can be used in previous Type-C ports, and other Type-C cables will work in USB4 ports, always automatically negotiating the fastest available speed. Speaking of "negotiating", USB4 has an ace up its sleeve: dynamic bandwidth allocation. For example: You have a USB4 port with a 40 Gbps link. On that same connection you plan to power a 4K monitor and transfer files to an external SSD. If the 4K monitor needs 12.5 Gbps, the other 27.5 Gbps will be free for the data copy, without conflicts.
What about availability? The original plan was "late 2020", but a certain virus turned everyone's "roadmaps" upside down, and we can't forget the fact that it will be more expensive to manufacture. In the most optimistic case (and with the wish that the world has improved a bit), USB4 will debut with new cables and devices in early/mid 2021. We'll be waiting.
Source: Lifehacker
