First Integrated Optical I/O Chiplet, Image/Intel
Revealed at the Optical Fiber Communication Conference (OFC) 2024 by Intel’s Integrated Photonics Solutions (IPS) Group, Intel Corporation has achieved a first with an integrated photonics technology for high-speed data transmission, the first integrated optical I/O chiplet.
Touted as the “industry’s most advanced and first-ever fully integrated optical compute interconnect (OCI) chiplet co-packaged with an Intel CPU and running live data.” The chiplet advances high-bandwidth interconnect by enabling co-packaged optical input/output (I/O) in emerging AI technology for data centers and high performance computing (HPC) applications.
Although the Intel OCI chiplet is considered a prototype, Intel has select customers to co-package OCI as a viable optical I/O solution.
Intel is no stranger to silicon photonics and is considered a pioneer leveraging more than 25 years of internal research from Intel Labs. Intel was the first company to develop and distribute silicon photonics-based connectivity products with industry-leading qualities to major cloud service providers.
As higher bandwidth, lower power consumption and longer reach become more important than ever to meet AI infrastructure’s increasing demands. CPU/GPU cluster connectivity and novel compute architectures are more scalable because of this technology:
This first OCI chiplet is designed to support 64 channels of 32 gigabits per second (Gbps) data transmission in each direction on up to 100 meters of fiber optics.
The chiplet also utilizes eight fiber pairs, each carrying eight dense wavelength division multiplexing (DWDM) wavelengths.
First Integrated Optical I/O Chiplet Pencil Eraser Comparison, Image/Intel
For example electrical I/O (i.e., copper trace connectivity) supports high bandwidth density and low power, but offers less reach of about one meter or less. Comparing electrical I/O with optical I/O in CPUs and GPUs to transfer data is akin to formally using horse-drawn carriages to distribute goods, on a small scale, to using today’s cars and trucks that can deliver goods on a much larger scale:
A co-packaged xPU optical I/O solution can support higher bandwidths with improved power efficiency, low latency and longer reach – exactly what AI/ML infrastructure scaling requires.
How does the fully Integrated OCI chiplet work? The chiplet uses silicon photonics technology and integrates a silicon photonics integrated circuit (PIC):
The fully Integrated OCI chiplet leverages Intel’s field-proven silicon photonics technology and integrates a silicon photonics integrated circuit (PIC), which includes on-chip lasers and optical amplifiers, with an electrical IC. The OCI chiplet demonstrated at OFC was co-packaged with an Intel CPU but can also be integrated with next-generation CPUs, GPUs, IPUs and other system-on-chips (SoCs).
This first OCI integration supports up to 4 terabits per second (Tbps) bidirectional data transfer, and is compatible with peripheral component interconnect express (PCIe) Gen5. The CPUs determined the optical Bit Error Rate (BER), and the demo showcases the transmitter (Tx) optical spectrum with 8 wavelengths at 200 gigahertz (GHz) spacing on a single fiber, with a 32 Gbps Tx eye diagram indicating strong signal quality.
Intel’s first integrated optical I/O chiplet signals a leap in AI infrastructure computing geared for high-speed data transmission essential for data centers and high performance computing (HPC) applications
