Hardware

USB4 vs. USB C

The benefits we get from USB are undeniably overwhelming, but the developments in the past few years have led to confusing version numbers. The USB 3.x generation has improved specifications, leading to many variations and different names for each improved version. We have seen variations such as USB 3.1, USB 3.2, USB 3.2 Gen 1×2, Superspeed, Superspeed+, and the likes. With the arrival of the latest USB4 in 2019, everything else seems much simpler, at least for now. Dubbed as the future USB, USB4 (yes, no space in between) comes with a host of powerful features comparable to Intel’s Thunderbolt 3. At times though, it is still confused with the latest USB connector that’s becoming the standard on most devices nowadays, the USB-C. To completely avoid all the confusion, let’s clear things out by getting into the details of how USB4 relates to USB-C.

What is USB4?

If you’ve been shopping around for new laptops or mobile devices, you’ve probably already seen the USB4 logo on them. That’s because newer devices already support the most recent USB version that’s packed with Thunderbolt 3’s protocols. In fact, USB4 is very much the same as Thunderbolt 3, but it’s royalty-free. Many devices can now enjoy Thunderbolt 3’s benefits without breaking the bank for Intel’s license. Just like Thunderbolt 3, USB4 exclusively uses a USB-C connector. Here are the features of USB4 that won’t let you think twice about upgrading your devices.

Speed

USB4 has two-speed variations; one that supports 20Gbps and another one that supports 40Gbps. USB 3.2 is capable of supporting 20Gbps, but no other version yet is capable of supporting 40Gbps. USB4 can deliver up to 40 Gbps of speed using the two-lane cables, making data transfer twice as fast as its predecessor’s.

DisplayPort Alt Mode 2.0

USB4 supports DisplayPort Alt Mode, which means it can transfer non-USB data, in this case, DisplayPort video data. Previous USB versions already implemented the Alt Mode support, but USB4 supports the latest version of Alt Mode, which is version 2.0.

Protocol Tunnelling

An even better video output support offered by USB4 is the DisplayPort and PCIe tunneling, where the DisplayPort, PCIe, and USB data packets can be sent simultaneously with dynamic allocation of bandwidth. In the previous versions, especially those that support the Alt Mode, the bandwidth is equally divided between video and USB data. If you run a monitor and transfer files from an external drive simultaneously, the bandwidth will be split into two. If the external drive only needs 25% of the allocated bandwidth, the remaining 75% will be left unused. What sets USB4 apart from the other versions is protocol tunneling which handles things a little differently and more efficiently. With protocol tunneling, the unused 75% of the bandwidth of the external drive is allocated to the video resource instead, giving it more bandwidth for faster data transmission.

USB Power Delivery (USB PD)

While it’s not standard for all USB-C ports to support USB PD, all USB4 ports are required to support USB PD, saving you the hassle of checking whether the port can supply power or not before plugging in your devices. USB PD can supply up to 100w of power, but the amount of power a USB4 port can provide does not necessarily equate to that amount. That would all depend on the device’s specs. Nonetheless, as long as there’s a device with a USB4 port around, you can charge your gadgets like your tablets or mobile phones through it in a flash.

Backward Compatibility

USB4 is backward compatible with the previous USB versions, including the much older USB 2.0. It’s noteworthy that devices with older USB versions won’t benefit from USB4’s speed since the speed will be downgraded to the lower version’s capability. Additionally, since USB4 exclusively uses the USB-C port, you need adapters to connect your older devices to the new port.

Similarly, USB4 is backward compatible with Thunderbolt 3 devices, but USB4 devices are not required to support Thunderbolt 3. If manufacturers wish to include Thunderbolt 3 support for USB4 devices, they have to obtain Intel’s license.

What’s the Difference Between USB4 and USB-C?

We’ve mentioned this ubiquitous connector in the USB4 discussion above several times, so we know that they both co-exist. It’s important to note that USB-C is not a rival nor a predecessor of USB4. As a matter of fact, they both work together to give you super-fast speed and other impeccable features of both standards.

USB Type C or simply USB-C is the new standard of USB connector that took over the previous USB standards in a sweep. The most notable feature of USB-C is its rounded design and flippability. Unlike with USB-A, where you need to connect your devices in the proper orientation, USB-C is more flexible, allowing you to insert the connector on any side. The cable is also reversible, so you don’t have to check which end goes to which device.

Aside from data transmission, USB-C can also provide power to host devices if it supports USB PD. In fact, newer devices have opted for the sleeker and lighter USB-C for a power supply rather than the bulky, traditional power adapters. Moreover, it’s capable of transmitting video signals, which means you can connect your DisplayPort, MHL, and HDMI devices to this multi-purpose port.

USB4 has superior features over the previous versions, and it’s only logical that it utilizes the superior USB-C connector. One important thing to remember is that while USB4 is exclusively using USB-C, USB-C is not tagged solely to USB4. In fact, it has already existed before USB4’s arrival and has been used by previous USB versions such as USB 3.2 and even Thunderbolt 3. Having said all that, there is no need to be confused between these two USB terms. To put it simply, USB-C refers to the physical design of cables and ports, while USB4 is a USB version that runs through USB-C.

About the author

Glynis Navarrete

A freelance blogger who loves to write about anything related to technology. Born and raised in the Philippines and worked in Singapore for eight years as Technical Support for a wide range of IT equipment. Took a dive into the world of freelancing and now enjoying doing what I’m passionate about while not losing touch with technology.