Intel made Thunderbolt 4 official and is already working on its successor. However, it has never been verified that a replacement is already in the works. Gregory Bryant, CEO of Intel's Client Computing Group, shared photographs of his visit to a development workshop on Twitter. One of these pictures showed the specifications of what Thunderbolt 5 should represent.

The Twitter tweet is still there, but there were originally four images. Three minutes later, a photo with the details has vanished.  Thunderbolt isn't addressed directly, but the terms '80G,' 'the current USB-C ecosystem,' and 'pam3' are noted.

80G is of course synonym to 80 Gb/s, which is twice as fast as Thunderbolt 3 and 4. The USB-C connection appears to be usable for this purpose. Pam3 is a two-cycle modulation method that sends three bits per two cycles. This is 50% quicker than nrz encoding. Pam4 already exists; this approach can transfer up to two bits every cycle, giving it a greater bandwidth at the same clock speed as Pam3. However, this is more difficult to execute and hence more expensive. This is likely one of the reasons Thunderbolt 5 does not appear to use it.

The presentation slide mentions that there is an N6-made test chip in the lab based on the new PHY. N6 is a TSMC manufacturing process, and judging by the sentence structure and line spacing, the chip appears to offer 'promising results'. Furthermore, the technology seems to be still in an early development phase, there is a good chance that it will take a few more years before we will see the technology in products.

Intel CEO shares a picture of Thunderbolt 5 features before hastily deleting it