At Intel Innovation 2022 this week, we noticed what is likely to be one of the vital fascinating items of expertise for servers, storage, and networking gear. It could possibly re-define the complete area. Particularly, that is the brand new Intel Silicon Photonics Connector. Allow us to get into what Intel is doing with the brand new answer and why it’s such a giant deal.
This Intel Silicon Photonics Connector is a HUGE Deal
At Intel Innovation 2022’s Day 1 keynote, Pat Gelsinger known as a Scottish Intel Lab and we witnessed a powerful demo of a brand new expertise. This can be a new pluggable kind issue for silicon photonics. A part of the reason being that the video and audio really labored, although that’s nonetheless not a given in 2022. The actual magic is that the Intel crew confirmed a reside demonstration of plugging in a brand new pluggable kind issue for co-packaged optics.
The way in which to consider what this pluggable optic module is, is that it’s a smaller model of a MPO/MTP connector that’s designed to attach on to chip packages.
Simply to visualise what this plugs into in your swap or NIC, the left 100GBASE-SR4 QSFP28 module on the left is the opposite finish for this cable. You’ll discover that, in contrast to the CWDM module (proper), a number of dense fibers are being related alongside this MTP-12 hyperlink. For the 100GBASE-SR4 there are 4 pairs, so eight of the 12 fibers are getting used, however these are the photographs we had available. In a few of Intel’s animations, they really begin with a MTP-12 cable after which present re-packaging it into the brand new silicon photonics connector.
That is delicate work. Right here is an instance of the cautious lab work taking place on this early unit.
Whereas many have seen networking pluggable optics, the present world of silicon photonics has a really bodily problem. Intel is aware of how one can manufacture silicon photonics modules, however placing them onto a chip is a problem as a result of one wants to attach fiber to the chip instantly. Many of the present approaches contain “pigtails” the place quick fiber runs go from the chip to a secondary connector.
These pigtails we’ve seen lately. One instance is the 4x 400G model we noticed at Intel Imaginative and prescient 2022.
We’ve seen these pigtails as effectively in our pre-pandemic Barefoot co-packaged optics piece. Right here you possibly can see the co-packaged optics pigtails that appear like those above related to MPO/MTP connectors in yellow.
For extra on that, right here is the video from when STH YouTube had 10,000 subscribers, pre-pandemic. STH YouTube simply hit 100,000 a few hours in the past.
Getting a bit into the demo we noticed on stage, Intel has a Photonic Built-in Circuit and an Digital Built-in Circuit collectively on the XPU package deal, after which that’s what is dealing with on-package electrical signaling to photonics. Retaining electrical signaling on a package deal is considerably decrease energy than driving alerts off-package. Given I/O energy calls for, that is going to be an enormous deal sooner or later. Community switches are already beginning to run into this problem simply given how a lot I/O they’ve. That might be one of many first segments to transition chips to co-packaged optics. It’s going to possible simply occur a technology or two later than what we confirmed in that 2020 piece.
Intel’s innovation is that one thing that appears like an AOC or lively optical cable, however is outwardly extra akin to a specialised multi-fiber connector like a MTP connector.
Should you look intently at Intel’s check package deal, there’s something else taking place. We are able to see one connector put in, however there look like areas for 2 extra which have black covers on on this picture.
Whereas which will appear far-fetched at first, think about Intel’s personal renderings depict a really comparable package deal with three connections. It appears like not solely is Intel delivering co-packaged silicon photonics with a pluggable connector kind issue, however they’re already engaged on multi-connector options with tons of bandwidth.
After all, with a number of fibers, one doesn’t must have particular fibers for reminiscence, community, compute, and storage, however the level is that is the imaginative and prescient. Intel can join gadgets via optical networking cables.
The “so what” of that is actually superior. Studying the tea leaves a bit, right here was Raja Koduri’s notes (with Cool Ranch Doritos) from the Raja’s Chip Notes Lay Out Intel’s Path to Zettascale piece:
You will notice one thing known as “Lightbender” or “Gentle bender” as a codename and “SiPh” shorthand for silicon photonics within the 2024-2025 period together with Falcon Shores.
Intel’s technique is to have a silicon photonics tile that it may well co-package with different sources and increase chips past present packaging expertise utilizing optical connections. Think about, as an alternative of being restricted to 6-8 HBM packages as a consequence of packaging concerns, that the HBM might sit off-package and related in through optics and thereby permit bigger HBM footprints.
We all know chips are going to a number of tiles as we see from UCIe, so this might be a silicon photonics tile that must incorporate some type of EIC and PIC as proven within the Innovation 2022 demo.
The place this additionally will get thrilling is that in CXL 3.0 we will have material topologies. If you wish to allow bigger rack-scale high-performance CXL communication, this might be a really helpful expertise.
The innovation proven at Innovation (sure that simply occurred) 2022, is just not that Intel can do silicon photonics. Hyper-scalers already purchase hundreds of thousands of silicon photonics modules in pluggable kind elements from Intel. One of many greatest challenges to co-packaged optics and the adoption of silicon photonics in chips is bodily how one can join them. The pigtail method is one that’s usually seen as difficult for real-world service. Intel confirmed its imaginative and prescient of going past optical pigtail bundles and to a well-recognized pluggable connector-based method. Whereas we might not be seeing the ultimate mechanical design, that is a type of small improvements the place we anticipate to see some kind issue standardized over the following few years on this space, and that to assist adoption. Between UCIe, CXL, and the next-generation of community switches, that is an space that wants a standard path ahead. That’s what makes the Intel Silicon Photonics Connector an enormous deal.