With the influence, social media have on our lives the influence which the various tech executives have on our lives is amazing. We have various executives visiting research divisions across the globe and they love to keep their followers sitting on the edge of their seats providing them with a lot more insights into the internal operations of various tech giants and what’s the next big thing they are working on.
However, when all this information is posted on social media we get to see some images which expose some unreleased information that is not meant for PR or isn’t even legal, but we get to see some outstanding tech that hasn’t yet appeared officially online.
This week, Gregory Bryant, the EVP, and GM of Intel’s Client Computing Group were spending some time at Intel’s Israel R&D facilities. This was his first overseas Intel trip of 2021 and this Sunday he posted a photo of himself showing the offices and the research.
However, his post contained four photos, which were rapidly deleted and replaced by a photo with three, you can see in the tweet above. The photo which was removed incidentally showcases some new information about next-generation Thunderbolt technology.
The deleted image showed a poster on the wall showcasing ‘80G PHY Technology’, meaning that Intel is working on a physical layer (PHY) for 80 Gbps connections. And this can only be the double bandwidth of Thunderbolt 4, which runs at 40 Gbps.
The second line on the poster also confirms that it is ‘USB 80G is targeted to support the existing USB-C ecosystem’, and this information comes after the news that Intel is aiming to maintain the USB-C connector but double the effective bandwidth.
However, the most interesting thing is the third line which states that ‘The PHY will be based on novel PAM-3 modulation technology’. This is the talk about how the 0 and 1s are transmitted which is the NRZ encoding. The natural progression is a scheme that allows two bits to be transferred, and this is called PAM-4 (Pulse Amplitude Modulation).
What exactly is the PAM-3 technology is that in it the data line can carry either a -1, a 0, or a +1. here the system combines two PAM-3 transmits into a 3-bit data signal, such as 000 is an -1 followed by a -1. This gets complex, so here is a table:
| PAM-3 Encoding | ||
| AnandTech | Transmit 1 | Transmit 2 |
| 000 | -1 | -1 |
| 001 | -1 | 0 |
| 010 | -1 | 1 |
| 011 | 0 | -1 |
| 100 | 0 | 1 |
| 101 | 1 | -1 |
| 110 | 1 | 0 |
| 111 | 1 | 1 |
| Unused | 0 | 0 |
When it comes to comparing the NRZ to PAM-3 and PAM-4, we found that the rate of data transfer for PAM-3 is in the middle of NRZ and PAM-4.
| NRZ vs PAM-3 vs PAM4 | |||
| AnandTech | Bits | Cycles | Bits Per Cycle |
| NRZ | 1 | 1 | 1 |
| PAM-3 | 3 | 2 | 1.5 |
| PAM-4 | 2 | 1 | 2 |
