What is USB 4: Everything You Need to Know [Complete Understanding for 2024]

For years, USB connections have been the backbone of various devices, but the specific ports used and required cables could vary greatly. With USB 4, you get more speed and power than ever before, and perhaps more standardization in the industry. Read on to learn all about this enticing USB bolt!

Introduction

USB 4 ushers in a new era of connectivity for USB users. In the coming years, USB 4 is expected to become the interface you use for just about everything, from faster data transfers, to output to external ultrahigh-definition displays, to connecting legacy USB devices and charging your gear.

Its intriguing features have USB enthusiasts eager to learn more about USB 4. If you're one of those curious about USB 4 and want to delve deeper into what it offers, then this article is tailored for you. Stick with us till the end, and you'll gain a comprehensive understanding of the most exciting new addition to the USB family.

What is USB 4?

Before diving into the details, let's first understand what USB 4 is. USB 4 is a USB system defined in the USB 4 Version 1.0 specification released by the USB Implementers Forum on August 29, 2019. Unlike previous USB protocol standards, USB 4 requires the use of a USB-C connector and USB Power Delivery (PD) functionality. It also supports DisplayPort and PCI Express tunneling compared to USB 3.2.

The design specifies a way to share high-speed links dynamically with multiple device types, adapting optimally to data transfers of different types and for different applications. While USB4 devices must be capable of 20 Gbps throughput and be backward-compatible with 40 Gbps, tunneling techniques mean that the effective data rate can be higher than in USB 3.2 even at the nominal 20 Gbps.

USB 4 Specification

The USB 4 specification builds upon and extends the current USB 3.2 and 2.0 architecture with the ThunderboltTM protocol definition, contributed by Intel Corporation. This enables maximum aggregated bandwidth to double that of USB and allows for multiple data and display protocols to be supported simultaneously.

To best support data transfers of different types and uses, the USB4 design specifies a technology that allows a single high-speed link to be shared dynamically among multiple classes of endpoint devices.

The USB 4 specification enables a host to flexibly evolve external display port functionality for many host products over a USB Type-C connection with appropriate management of display data streams. The resulting connection scales to the best common capability of the connected devices and supports compatibility with existing USB 3.2, USB 2.0, and Thunderbolt 3 hosts and devices.

Here are the key features of USB 4:

• Operation at up to 40 Gbps over certified 40 Gbps cables, and dual-lane operation over existing USB Type-C cables.
• Efficient sharing of the maximum aggregated bus bandwidth with a variety of data and display protocols.
• Compatibility with Thunderbolt 3, USB 3.2, and USB 2.0.

What are USB 4 ports used for?

Though there aren't many products billing themselves as USB 4 yet, a new generation of USB 4-powered docks and peripherals is arriving. Among the promised benefits of USB 4 are faster data-transfer rates, improved video-bandwidth management, and optional Thunderbolt 3 compatibility.

Here are some key milestones to watch for in the rollout of USB 4:

• It's used to interface with devices that have a USB Type-C connection. USB4 is a communication standard or protocol that allows a computer to communicate with a device over a USB-C connection. All three of these technologies use the USB-C connector type to connect to computers and devices.
• If you need to improve your video quality without changing connectors, USB4 is a good choice. USB4 devices can use a mechanism called "protocol tunneling" to simultaneously transmit DisplayPort, PCIe, and USB packets and allocate bandwidth proportionally without switching to another interface.
• You can transfer all your data at once without compromising your display with USB4. DisplayPort 2.0 can support 8K resolution at 60 frames per second with HDR10 color. Because it sends all its data in one direction (to the monitor), it can use all eight of its data lanes simultaneously, for a maximum bandwidth of 80 Gbps, which is double the available bandwidth for USB data.

Is USB 4 the same as USB-C or Thunderbolt?

Now that you're familiar with the capabilities and applications of USB 4, let's discuss how it differs from previous USB ports.

With USB-C and Thunderbolt, USB 4 makes huge strides and changes the game for plain old USB. While USB 3.0, 3.1, and even USB 3.2 connections allowed for cheaper devices to achieve 5 Gbps transfers, USB 4 requires at least 10 Gbps, with most devices supporting the 20 Gbps USB 4 data rates approved by the USB-IF.

USB 4 vs. USB-C: What's the Difference?

At first glance, USB 4 and USB-C seem interchangeable, but they actually refer to two very different technologies. USB-C is a specific type of cable, while USB 4.0 is a specific advancement in USB cable technology. The shape has nothing to do with USB 4; it refers to the exact technology inside the USB-C. Yes, your cable might support both USB 4 and USB-C. Just to add to the confusion, you can't tell if a device is USB 3 or USB 4 just by looking at it. While USB 3 does work with the newer USB-C architecture, some USB 3 connections still use the older USB-A design.

USB 4 vs. Thunderbolt: Which Is Better?

If USB 4 sounds great, that's because it is – but it's not the only game in town. Thunderbolt 4 has similar virtues and will soon be another important connection standard to look out for. It also uses a USB-C port and transfers data at up to 40 gigabits per second.

Now, you can connect up to five Thunderbolt devices on a single PC. It also handles two displays simultaneously and requires a higher minimum power (15W for Thunderbolt, 7.5W for USB4). Here's a chart comparing USB4 and Thunderbolt 4:

The advantages of USB 4 over other USB types like USB 3.0

USB 4 is indeed one of the best features introduced in the USB port family. It meets all the standards of modern USB, compared to USB 3, from specifications to functionalities. Here's a chart outlining the key differences between USB 4 and USB 3.

Can USB 4 use a Type-C connector?

The USB-C cable is a modern USB connector that is more powerful and user-friendly than its predecessors. It can charge popular devices like the MacBook Pro and the Nintendo Switch much faster than any other USB type. With USB 4, the old-style USB Type A port will be gone, to be replaced only by USB-C connectors. That's no surprise, because only USB-C supports new standards like USB Power Delivery.

Bottom line

It's all but certain that USB 4 hosts and devices will be faster and more capable than their USB 3 predecessors. Like Thunderbolt 4, it aims to raise the performance floor for USB and introduce some cool new features to make the standard more compatible with current devices.

Ultimately, USB 4 aims to unify the USB standard with new performance and features. Though different devices will still support different speeds, the ubiquitous USB-C connector will be simpler, and improved power-delivery options will mean fewer cables and chargers cluttering users' homes.

FAQ: Everything You Need to Know About USB 4

By now, you probably have an idea of what USB 4 is, but there are still some questions to be answered about it!

What's the difference between USB 4 and USB-C?

One of the main – and most obvious – differences between USB 4.0 and USB-C is that USB-C is a form factor for a USB cable.

This refers to the physical design of connectors and ports, while USB 4.0 focuses on the functionality and speed of USB cables. In short, USB 4.0 is the latest version of USB embedded within a USB-C cable.

One difference is that while the actual USB-C connector is not backward-compatible, the underlying USB specification is. A legacy USB device will not plug into a modern, small USB-C connector.

Unlike USB-C, which can't connect to earlier, bigger USB ports, USB 4.0 has fewer restrictions and is fully backward-compatible with earlier versions.

2. What kind of USB 4 devices can I buy?

There are many products that support USB 4 technology, some of which are listed below. However, before purchasing, it's essential to carefully check the product name, as USB 4 products often prominently indicate "USB 4" in their labeling.

USB 4 SSDs: USB 4 SSDs are among the fastest drives out there. If you're looking for the best solution for an SSD drive with top performance, a USB 4 SSD is an excellent choice.

USB 4 Enclosures: USB 4 enclosures offer various benefits, such as increased transfer speeds, improved video handling, and optional compatibility.

USB 4 cable: In addition to delivering the best video quality, USB 4 technology unlocks unused bandwidth over a single cable for power, data transfer, and more.

3. Which type of USB is right for you?

After understanding the differences between USB-C and USB 4, you'll realize that you're not choosing between the two, because if you buy a USB 4 device, it will use a USB-C design.

So which one should you pick? For most users, probably either USB4 or Thunderbolt 4, since they're so similar that you might not have a preference.

USB 4 is the next iteration of USB and is widely compatible. It charges quickly, can support multiple devices at once, transfers data quickly, and requires fewer connections than previous USB technologies. If you like USB, it makes sense to continue using it.