The Importance of 800G Optical Modules in AI Wave

NADDOD Gavin InfiniBand Network Engineer Mar 6, 2024

In the era of artificial intelligence, the emergence of 800G optical modules is crucial for meeting the high-speed data transmission demands. Compared to 200G and 400G optical modules, 800G optical modules not only provide higher transmission rates and larger deployment scales but also prioritize energy efficiency and sustainability. This makes them essential components in applications involving artificial intelligence and other high-performance computing, offering robust solutions for fast and reliable data transmission. Moreover, they lay the foundation for future technological advancements.This article delves into the evolution of 800G optical modules and their tremendous potential in the era of artificial intelligence.


1. The Evolution of 800G Optical Modules

The evolution of 800G optical modules is based on the continuous development of optoelectronic devices and integration technologies. Over time, the performance and transmission bandwidth of optical modules have been continuously improved. From the initial 100G, 200G, and 400G to the current 800G optical modules, the transmission rates have significantly increased. At the same time, the size of optical modules has been continuously reduced, resulting in more compact packaging. This allows optical modules to adapt to different usage scenarios, providing higher port density while reducing the demand for rack space.


With the rapid development of artificial intelligence, cloud computing, and big data applications, the demand for high-speed data transmission has become increasingly urgent. People require efficient processing and transmission of large volumes of data to support various AI tasks and applications such as machine learning training, image recognition, and speech processing. 800G High-speed optical modules provide one of the primary solutions to meet these demands.


Increasing Bandwidth Requirements

The growing demand for bandwidth has had a significant impact on high-speed optical modules. Traditional 100G, 200G, and 400G optical modules are no longer sufficient to meet the market's needs, given the emergence of new technologies and the demand for large-scale data transmission. To address the ever-increasing bandwidth requirements, 800G optical modules are now becoming a trend.


Higher Transmission Rates


Compared to 100G, 200G, and 400G optical modules, 800G optical modules offer significantly improved transmission rates. They can transfer more data in shorter periods of time to meet the requirements of high bandwidth and low latency. This is critical for fast processing and analysis of large-scale datasets, enhancing the performance and efficiency of AI systems.


Support for Larger-Scale Deployments


As AI applications become more prevalent, scalable deployments have become increasingly important. The emergence of 800G optical modules enables higher port density in data centers and cloud computing environments. This means that more servers and devices can be connected through fiber optic networks, providing greater computing and storage capacity to meet the growing demands of data processing.


Growth of LPO Technology

The adoption of Low Phase Noise Amplifier (LPO) technology in 800G optical modules enables lower bit error rates in high-speed data transmission. LPO technology reduces the generation of phase noise by minimizing the nonlinear effects in signal amplification. This allows for more accurate signal transmission, reducing interference and distortion during transmission and improving data reliability and integrity.Furthermore, LPO technology can enhance the energy efficiency of optical modules. By reducing the generation of phase noise, LPO technology lowers the power consumption of the optical module. This is crucial for meeting energy-saving and sustainability requirements and helps reduce operational costs in data centers.


2. 800G Optical Module Packaging Type

With the continuous advancement of technology, the packaging of optical modules has undergone significant evolution. It has transitioned from the early GBIC packaging to the smaller SFP packaging, and now to the current 800G QSFP-DD and OSFP packaging. This development trend not only reflects the continuous improvement of optical module speeds but also demonstrates its progress towards miniaturization and hot-pluggable capabilities. The application scenarios for 800G optical modules are becoming increasingly widespread, covering various fields such as Ethernet, CWDM/DWDM, connectors, fiber channels, and wired/wireless access.


QSFP-DD vs OSFP size

800G QSFP-DD Form Factor:


The QSFP-DD is a double-density, four-channel, small form-factor pluggable high-speed module. It is the preferred packaging for 800G optical modules, enabling efficient growth and scalability of cloud capacity in data centers. The QSFP-DD module features an 8-channel electrical interface, with each channel supporting speeds of up to 25Gb/s (NRZ modulation) or 50Gb/s (PAM4 modulation), providing aggregation solutions of up to 200Gb/s or 400Gb/s.


  • Advantages of 800G QSFP-DD:


  1. Downward compatibility, compatible with QSFP+/QSFP28/QSFP56 form factors.


  1. Utilizes a 2x1 stacked integrated cage connector, supporting both single-high and double-high cage connector systems.


  1. Offers at least 12 watts of thermal capacity per module through SMT connectors and 1xN cages.


  1. Higher thermal capacity reduces the thermal management requirements of optical modules, thereby reducing unnecessary costs.


  1. The design of QSFP-DD, with ASIC implementation, enables flexibility for users by supporting multiple interface rates and backward compatibility (compatible with QSFP+/QSFP28), reducing port costs and equipment deployment costs.


800G OSFP Form Factor:


OSFP is a new form factor for optical modules, significantly smaller than CFP8 but slightly larger than QSFP-DD. It features eight high-speed electrical channels and can support up to 32 OSFP ports on a 1U front panel with integrated heat sinks to enhance thermal performance.


  • Advantages of 800G OSFP:


  1. The OSFP module is designed with eight channels, directly supporting a total throughput of up to 800G, thus achieving higher bandwidth density.


  1. Due to the support for more channels and higher data transmission rates, OSFP packaging can provide higher performance and longer transmission distances.


  1. The OSFP module features excellent thermal design, allowing it to handle higher power consumption.


  1. OSFP is intended to support future higher rates. With its larger form factor, OSFP has the potential to support higher power consumption, enabling higher rates such as 1.6T or beyond.


  • Comparison of External Parameters of 800G Optical Modules:



QSFP-DD is typically the preferred choice for telecom applications, while OSFP is more suitable for data center environments. The main differences between the two are:


  1. Size: OSFP has a slightly larger form factor.


  1. Power consumption:OSFP has slightly higher power consumption compared to QSFP-DD.


  1. Compatibility: QSFP-DD is fully compatible with QSFP28 and QSFP+ form factors, while OSFP is not compatible.


3. 800G Optical Module Type Distinction


800G = 8 * 100G = 4 * 200G, so it can be divided into two categories based on the single-channel rate, namely single-channel 100G and 200G. The corresponding architectures are shown in the diagram below. Single-channel 100G optical modules can be quickly implemented, while 200G requires higher demands on the optical components. Since the maximum speed supported by current electrical interfaces is 112Gbps PAM4, a gearbox is required to convert for the single-channel 200G case.



For multimode applications, there are primarily two standards for 800G optical modules, which correspond to distances less than 100m.


1. Multimode Fiber (MMF) Modules:

It uses the VCSEL technology with a wavelength of 850nm and operates at a single-channel rate of 100Gbps PAM4. It requires 16 fibers for transmission. This can be seen as an upgraded version of the 400G SR4 module with double the number of channels. The optical interface is either MPO-16 or a dual-row MPO-12, as shown in the diagram below. The 800G SR8 optical module is commonly used for 800G Ethernet, data center links, or 800G-800G interconnects.



This solution uses wavelengths of 850nm/910nm for bidirectional transmission, with the two wavelengths separated by a DeMux within the module. The single-channel rate is 100Gbps PAM4, and it requires 8 fibers for transmission. Compared to SR8, this solution reduces the number of fibers by half. The block diagram is shown in the diagram below.



The fiber interface is shown in the diagram below, which utilizes an MPO-12 interface.


MPO-12 bidi

For single-mode applications, there are several standards for 800G optical modules:


2. Single-Channel Modules for Metro and Long-Haul Applications:


This module operates at a single-channel rate of 200Gbps over SMF and requires two fibers. It supports distances of up to 2km and uses dual LC duplex interfaces.


800G 2xFR4-1

It uses a duplex LC optical interface, as shown in the figure below.


Duplex LC

This module operates at a single-channel rate of 100Gbps and uses eight wavelengths, requiring two fibers. It supports distances of up to 2km and utilizes dual LC duplex interfaces.The eight wavelength channels are 1271/1291/1311/1331/1351/1371/1391/1411nm.


800G FR8

3. Single-Mode Fiber (SMF) Modules


800G DR8, 800G 2xDR4, and 800G PSM8: These modules use eight channels, each operating at a single-channel rate of 100Gbps over single-mode fiber. They require 16 fibers for transmission and are suitable for data center interconnects, supporting distances up to 500m (DR8) or 100m (PSM8).



The 800G DR8 optical module utilizes 100G PAM4 and 8-channel single-mode parallel technology. It can achieve a transmission distance of up to 500m over single-mode fiber and is commonly used for data center interconnects, 800G-800G, 800G-400G, and 800G-100G connections.



The term "800G 2 x DR4" refers to two "400G-DR4" interfaces. The optical interface for 2DR4 consists of two MPO-12 connectors, as shown in the diagram below. It can be interconnected with 400G DR4 optical modules without the need for fiber breakout cables, supporting a transmission distance of 500m. This facilitates data center upgrades. PSM8 and DR8 have an MPO-16 optical interface.


 Dual MPO-12

  • 800G PSM8


The 800G PSM8 utilizes CWDM technology and features eight optical channels, with each channel having a transmission rate of 100Gbps. It supports a transmission distance of 100m and is particularly suitable for long-distance transmission and fiber resource sharing.




These two standards have similar internal structures, both consisting of four wavelengths and operating at a single-channel rate of 100Gbps. By using a Mux, the number of fibers is reduced to four, as shown in the diagram below.


800G 2xFR4

These two solutions are upgrades of the 400G FR4 and LR4 optical modules, utilizing the CWDM4 wavelength range of 1271/1291/1311/1331nm. The 2xFR4 supports a transmission distance of 2km, while the 2xLR4 supports a transmission distance of 10km. The optical interfaces used are either dual CS or dual duplex LC connectors.


4. The impact of AI on 800G Optical Modules


For AI servers, here are a few reasons why 800G is more important than 400G:


  1. High data transfer rate and low latency requirements: AI applications often require large amounts of data transfer and processing, especially when training deep learning models. The 800G optical module provides a higher transfer rate and lower latency, enabling more efficient support for large-scale data transfer and computation needs.


  1. Scale and architecture of AI servers: AI servers are typically deployed in large-scale clusters or centralized setups, requiring high-bandwidth spine switches. The 800G optical module can provide greater network capacity, supporting high-speed communication between a larger number of server nodes.


  1. Cost efficiency and economic benefits: 800G optical chips utilize more advanced technology and designs, offering better cost efficiency and economic benefits compared to 400G optical chips. Using fewer optical chips to achieve the same transfer rate can lower costs and improve overall economic efficiency.


Although 800G optical modules are important for AI server deployments, 400G optical modules still have significant industry-wide applications. They provide a significant bandwidth improvement and are sufficient for certain application scenarios. Additionally, due to technological and cost considerations, some organizations may choose to use 400G optical modules in their existing infrastructure instead of directly upgrading to 800G.NADDOD's 800G optical modules/AOCs/DACs, as high-performance fiber optic transmission devices, provide a stable and reliable solution while meeting high-speed transmission requirements.


We have sufficient and stable inventory, with fast delivery speed, and have completed product deliveries for multiple companies, ensuring that orders can be delivered within two weeks. Additionally, each product is 100% tested on real devices, including testing scenarios with tens of thousands of simultaneous applications to ensure smooth operation and better meet real-world application needs. NADDOD optical modules have an extremely low bit error rate and utilize state-of-the-art Broadcom VCSEL chips.


NADDOD is your trusted supplier of optical modules and high-speed cables! Please feel free to contact us for preferential quotations!