According to the leaked photo, Thunderbolt 5 should double the speed of the previous generation and transfer data at 80 Gb/s in USB-C standard
Soon after posting the photos, Bryant deleted the tweet and reposted three more images afterward. The original photos — saved in time by AnandTech — showed the executive vice president alongside other company employees in various areas of Intel Israel’s research and development labs.
In one of the images, Bryant was shown visiting a room with a poster on the wall that read “80G PHY Technology”. The term means that Intel may be working on a physical layer technology (PHY, for physical) for 80Gb/s connections. Compared to the previous generation, this is twice the speed of Thunderbolt 4, which runs at 40 Gb/s.
Also in the poster message, there was an excerpt with the following information: “The USB 80G is designed to support the current USB-C ecosystem”. In other words, Intel plans to double the Thunderbolt 5 connection bandwidth without changing the USB-C standard already known in the market.
Thunderbolt 5 to innovate with PAM-3 technology
Later on, the text spoke of adding a “first-time technology” to Thunderbolt 5: “The PHY will be based on an original PAM-3 modulation technology”. PAM stands for “Pulse Amplitude Modulation” — or Pulse Amplitude Modulation in English — and is a multilevel signal modulation format used to transmit data.
Typically, connections involving data transfer are based on NRZ (non-return-to-zero) or PAM-4. Whereas NRZ signals are binary — just 0 and 1 —, PAM-4 signals vary by two bits — such as 00, 01, 10, or 11. PAM-3, on the other hand, falls between the two patterns and uses the values -1, 0, and +1.
With this, Intel should achieve higher bandwidth more simply, without the limitations that PAM-4 requires to be enabled. The PAM-3 is very similar to the NRZ, but it manages to be more efficient.
In the end, the message even said that “…the N6 test chip focusing on the new PHY technology is running on […] showing promising results”. It was not possible to read the entire text because the Intel employee who accompanied Bryant covered part of the poster, but it is possible to say that the work on Thunderbolt 5 is producing the results desired by the company.