With Thunderbolt 5, Intel has doubled the interface’s bandwidth to 80 Gbps in each direction. In practical terms, it’s now capable of handling three 4K displays and supports refresh rates as high as 540Hz. In fact, video-intensive workloads can trigger a new “bandwidth boost” feature that allocates an additional 40 Gbps lane, allowing Thunderbolt 5 to carry 120 Gbps in one direction. That’s three times more bandwidth than Thunderbolt 3 and 4.
Thunderbolt 5's bandwidth boost feature unlocks true 8K display support.
Thunderbolt 5 also improves data transfer speeds, supporting up to 64 Gbps via the PCI Express Gen 4 interface. This means you can now use some of the highest-end SSDs in an external enclosure. Moreover, the use of PCIe Gen 4 also lets you connect external graphics card enclosures. In previous Thunderbolt generations, these enclosures were limited to 32 Gbps speeds, which was a big bottleneck for high-end desktop GPUs that needed more bandwidth.
The final big improvement going from Thunderbolt 4 to Thunderbolt 5 comes in the form of power delivery, with the newer version capable of delivering a mini mum of 140W. That’s already a fair bit higher than the previous generation’s 100W figure, but manufacturers can also configure it to deliver up to 240W. We have yet to see laptop manufacturers adopt USB Power Delivery’s 240W mode, but Thunderbolt 5 supporting it is a good sign nevertheless. The connector’s improved charging spec will come in handy for powerful gaming laptops, most of which currently rely on a DC barrel connector to meet their power needs.
Thunderbolt 5 is backward compatible with prior generations of the interface. If you plug a Thunderbolt 4 accessory into a Thunderbolt 5-capable port on a computer, the two devices will still recognize and communicate with each other. You’ll simply be limited to the slowest link in the chain, which is Thunderbolt 4 in this example. The same is true for the opposite scenario as well; you can plug a new Thunderbolt 5 accessory into an older Thunderbolt 4 port.
Even though Thunderbolt 5 represents a big leap forward, it’s only a meaningful upgrade for users of external displays and graphics. For this reason, Intel expects gamers and content creators to adopt the new interface first, with workstation users to follow later. Existing Thunderbolt 4 docks already have enough bandwidth to support less demanding peripherals.