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Is Thunderbolt 4 Backwards Compatible with Thunderbolt 3?

Is Thunderbolt 4 Backwards Compatible with Thunderbolt 3_

The latest Thunderbolt 4 interface is less about raw speed and more about device charging and display connectivity.

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Also Read: List of the Best Thunderbolt 3 PCIe Cards & Expansion Systems

Thunderbolt 4 can be described as the interface to terminate all ports in simple terms. It represents an advancement of Thunderbolt 3 and still utilizes the USB Type-C connector. Like preceding iterations, it supports DisplayPort, PCIe, and USB signaling through a single cable (with a length of up to 2 meters).

Intel formally declared Thunderbolt 4 in early 2020. It started shipping in 11th generation Core-based laptops in the fall of 2020 and early 2021. Compared to the previous Thunderbolt 3 interface, the minimum PCIe link bandwidth requirements in Thunderbolt 4 increased from 16 Gbps to 32 Gbps.

Also, it added support for dual 4K displays @ 60 Hz through the DisplayPort 1.4 protocol.

There is another improvement compared to Thunderbolt 3, i.e., the capability to support accessories with up to 4 Thunderbolt ports, support for Intel VT-d DMA (Direct Memory Access) protection for virtual machines, and wake a PC from sleep.

Thunderbolt 4 can support up to 40 Gbps bi-directional bandwidth. This aspect makes it a perfect interface for PC-to-PC data transfers, the finest SSD storage solutions, and the external GPU docks such as the Razer Core X.

Currently, Thunderbolt 4 ports can be found on Intel-based laptops and desktops, along with Apple’s latest Macs and iPad Pro product lines.

Thunderbolt 4 is a significant evolution of the multipurpose, high-speed standard. It authorizes essential features like a 32Gbps PCI-Express data speed, at least 40 Gbps bandwidth, and support for more concurrent 4K displays.

Also, it arouses the demands of the host system, not only on the port itself. This makes Thunderbolt 4 support a significant mark of quality and a competent connector type.

Thunderbolt™ 4Thunderbolt™ 3
One universal computer port
Universal 40Gb/s cables up to 2 meters in length
Accessories with four Thunderbolt ports
Minimum PC speed requirements40Gb/s40Gb/s
Minimum PC video requirementsTwo 4K displaysOne 4K display
Minimum PC data requirementsPCIe 32 Gb/s USB 3.2 10Gb/sPCIe 16 Gb/s USB 3.2 10Gb/s
Required PC charging on at least one computer port1
Required PC wake from sleep when the computer is connected to a Thunderbolt dock
Minimum PC port power for accessories15W15W
Thunderbolt Networking
Mandatory certification for all shipping computers, accessories, and cables
Cable testing and cable quality audits for Thunderbolt cable manufacturers
Required Intel VT-d based DMA protection
USB4 SpecificationCompliantCompatible

Thunderbolt 4 ports are compatible with several connection standards like previous versions of Thunderbolt, DisplayPort, USB, and PCle. This port fits into standard USB-C type connectors.

The important question is – is Thunderbolt 4 backward compatible? Yes, and this adds another essential feature to its existing impressive set of features.

What can you connect with Thunderbolt 4?

You can connect Thunderbolt devices, external monitors, USB peripherals, PCI Express (PCIe) devices, and networking devices.

Its charging ability helps you to connect your lightweight notebook PC (that needs less than 100W), a phone, and other compatible USB devices to charge them quickly.

What is Thunderbolt 4 backward compatible with?

Thunderbolt 4 is found to be backward compatible with various standards. Thunderbolt 4 certified cables can use older and alternative port standards. Moreover, Thunderbolt 4 ports are capable of using cable standards.

Thunderbolt 3 is entirely supported by Thunderbolt 4. It implies that you can plug Thunderbolt 4 cables in Thunderbolt 3 ports (though it is not guaranteed to obtain the same speeds or functionalities).

Thunderbolt 3 cables are entirely compatible with Thunderbolt 4 ports. It is important to note that you can still enjoy lots of the identical Thunderbolt 4 features in the latter case if the Thunderbolt 3 cable is certified at 40 Gbps.

Thunderbolt 4 is not only backward compatible with its predecessors, but it also utilizes the USB-C form factor for connecting to its interface. Also, you can directly plug USB-C cables into Thunderbolt 4 ports which allow them to work at up to USB-C 3.2 Gen 2×2 speeds.

Thunderbolt 4 is also backward compatible with USB 4 and is frequently advertised as such. Apple demonstrates its devices with Thunderbolt/ USB 4 support in the latest line of MacBooks.

The official specifications of Thunderbolt 4 list it as “compliant” with USB 4. On the other hand, Thunderbolt 3 has been consigned to being only “compatible” with the alternative connection standard.

Is Thunderbolt 4 backward compatible with Thunderbolt and Thunderbolt 2?

Thunderbolt 4 is designed with the help of the USB-C connector, similar to Thunderbolt 3 was. It is entirely incompatible with the older Thunderbolt and Thunderbolt 2 standards (prepared using the Mini DisplayPort connector).

Cable Matters sells certain Mini DisplayPort to USB-C cables that might function in certain niche cases. However, the official specification demonstrates that Thunderbolt 4 is not backward compatible with such older standards. Hence, it is not guaranteed that they will work properly.

Is Thunderbolt 4 backward compatible with daisy chaining?

Like Thunderbolt 3, Thunderbolt 4 will support daisy-chaining to operate multiple displays from a single Thunderbolt port.

In addition, Thunderbolt 4 supports Thunderbolt Alternate Mode USB hubs and daisy-chaining too. Such hubs are backward compatible with Thunderbolt 3 devices as well.

This is specifically significant with Thunderbolt 4, which assures a minimum PC data requirement of 32 Gbps over PCI-Express. Consequently, it enables support for a minimum of two 4K displays.

The Thunderbolt 4 standard makes it simpler to connect an array of displays to your compatible devices, facilitating additional display support and extending support for alternate mode USB hubs. Although those hubs were originally built considering Thunderbolt 3, Thunderbolt 4 allows you to explore the maximum benefits.

Is it necessary to use Thunderbolt 4 cable with Thunderbolt 4?

Considering the backward compatibility of Thunderbolt 4, you can certainly get by without utilizing a Thunderbolt 4 cable. Like what happens with Thunderbolt 3, a lightning bolt symbol will be used to label Thunderbolt 4 docks. So, if support is a priority for you, you can check out the specifications of your device manufacturer.

But Thunderbolt 4 cables will be labeled with a lightning bolt logo and a tiny number 4 beneath it.

There is no instant need to use Thunderbolt 4 cables even though you can access a high-quality Thunderbolt 3 cable. They are designed with the highest standard and can offer enhanced future-proofing against Thunderbolt upgrades in the future.

Furthermore, all Thunderbolt 4 cables are rated to support the maximum data rate of 40 Gbps at up to 2M. On the other hand, not all Thunderbolt 3 cables can guarantee this speed. This can prove vital while working with external monitors in which shorter cables can restrict placement.

Thunderbolt 4 cables are also more advantageous than conventional USB-C cables. Though it seems excessive for some uses, the broad Thunderbolt 4 backward compatibility and feature support suggest that Thunderbolt 4 is the most extensive and capable cable type for 2022 and the future.

Where can you buy Thunderbolt 4 cables?

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