Leaked details of Intel’s upcoming next-generation Thunderbolt 5 hardware interface protocol indicate that Thunderbolt 5 bandwidth will double to 80Gbps. The details were accidentally revealed in a tweet by an Intel executive.
The details appeared in a since-deleted Sunday tweet by EVP and GM of Intel’s Client Computing Group, Gregory Bryant, who was documenting his visit to Intel’s R&D labs in Israel.
As reported by AnandTech, the tweeted photo Thunderbolt-related tour revealed a poster on a lab wall with the words “80G PHY Technology”
In this image we can see a poster on the wall showcasing ‘80G PHY Technology’, which means that Intel is working on a physical layer (PHY) for 80 Gbps connections. Off the bat this is double the bandwidth of Thunderbolt 4, which runs at 40 Gbps.
The second line confirms that this is ‘USB 80G is targeted to support the existing USB-C ecosystem’, which follows along that Intel is aiming to maintain the USB-C connector but double the effective bandwidth.
The third line is actually where it gets technically interesting. ‘The PHY will be based on novel PAM-3 modulation technology’. This is talking about how the 0 and 1s are transmitted – traditionally we talk about NRZ encoding, which just allows for a 0 or a 1 to be transmitted, or a single bit. The natural progression is a scheme allowing two bits to be transferred, and this is called PAM-4 (Pulse Amplitude Modulation), with the 4 being the demarcation for how many different variants two bits could be seen (either as 00, 01, 10, or 11). PAM-4, at the same frequency, thus has 2x the bandwidth of an NRZ connection.
The poster also showed the sentence “USB 80G is targeted to support the existing USB-C ecosystem,” which indicates that Intel is aiming to maintain the USB-C connector but double the effective bandwidth.
Intel launched Thunderbolt 4 last year. However, Apple’s latest Macs and iPad Pro models still only support Thunderbolt 3. While TB4 offers more power and is backward compatible, it doesn’t offer any bandwidth increase from TB3.
(Image credit: AnandTech)