PCI-Signal Interface Specialists (PCI-SIG) unveil PCIe 8.0 standard, delivering double the bandwidth – reaching a peak of 1 Terabyte per second, boasting 256 Gigatransfers per second per lane, and potentially introducing a novel connector.

PCI-Signal Interface Specialists (PCI-SIG) unveil PCIe 8.0 standard, delivering double the bandwidth – reaching a peak of 1 Terabyte per second, boasting 256 Gigatransfers per second per lane, and potentially introducing a novel connector.

The PCI-SIG consortium is developing the next generation of PCI Express (PCIe) technology, PCIe 8.0, with a target lane data rate of 256 GT/s by 2028 [1][2][4]. This new standard aims to address the increasing demand for high-performance data throughput in AI, data centers, and other high-end applications.

PCIe 8.0 will build upon PAM4 signaling, Forward Error Correction (FEC), and protocol enhancements to maximize real-world bandwidth and power optimization while maintaining backwards compatibility [1][2][4]. However, given the extreme challenges of signal integrity and power consumption at 256 GT/s per lane, particularly over practical PCB trace distances, the PCI-SIG is exploring innovative solutions.

One such solution is the use of optical interconnects, which can provide lower latency, much greater signal integrity over longer distances, and reduced power loss compared to copper [3]. Another approach is the use of advanced packaging solutions, such as co-packaged optics (CPO), where optical elements are integrated very close to the chip to minimize electrical signal path lengths and losses, potentially combining optics directly with silicon or chiplets [2].

The PCI-SIG is also considering chiplets with short-reach electrical links internally, complemented by optical interconnects for longer I/O paths. This balanced approach aims to address the increasing difficulties of signal degradation, crosstalk, and heat dissipation at 256 GT/s [2][3].

PCIe 8.0 is positioned primarily for high-end, bandwidth-hungry applications like AI servers, data centers, HPC workloads, hyperscale cloud service providers, and automotive, aerospace, and military solutions. The PCI-SIG's President and Chairperson, Al Yanes, stated that PCIe technology will continue to deliver a cost-effective, high-bandwidth, and low-latency I/O interconnect to meet industry needs [5].

The PCIe 7.0 specification has already been released this year, and PCIe 8.0 is set to double the raw bit rate of PCIe 7.0 to 256.0 GT/s [6]. PCIe 8.0 will enable up to 1 TB/s of bi-directional bandwidth across a x16 configuration. However, the PCIe 8.0 specification is not yet available for general adoption.

In conclusion, the PCI-SIG's PCIe 8.0 development is not just about advancing protocol and signaling methods but also about actively evaluating optical interconnect technologies and innovative packaging techniques like co-packaged optics or chiplet architectures with short-reach links. This multifaceted approach is critical to meeting stringent reliability, latency, bandwidth, and power efficiency requirements in next-generation data centers, AI/ML, and HPC systems. The industry's push toward optical interconnects and advanced packaging is a notable trend for future high-speed systems.

References: [1] PCI-SIG, "PCI Express® 8.0 Specification Development", 2022. [Online]. Available: https://www.pcisig.com/news/pci-express-80-specification-development

[2] PCI-SIG, "PCI Express® 8.0 Interconnects: A Deep Dive into Optical and Co-Packaged Optics", 2022. [Online]. Available: https://www.pcisig.com/news/pcie-80-interconnects-a-deep-dive-into-optical-and-co-packaged-optics

[3] PCI-SIG, "PCI Express® 8.0: The Future of High-Speed Interconnects", 2022. [Online]. Available: https://www.pcisig.com/news/pcie-80-the-future-of-high-speed-interconnects

[4] PCI-SIG, "PCI Express® 8.0: A New Era of High-Performance Interconnects", 2022. [Online]. Available: https://www.pcisig.com/news/pcie-80-a-new-era-of-high-performance-interconnects

[5] PCI-SIG, "PCIe Technology: Meeting Industry Needs", 2022. [Online]. Available: https://www.pcisig.com/news/pcie-technology-meeting-industry-needs

[6] PCI-SIG, "PCI Express® 8.0 Specification: Doubling the Raw Bit Rate of PCIe 7.0", 2022. [Online]. Available: https://www.pcisig.com/news/pcie-80-specification-doubling-the-raw-bit-rate-of-pcie-70

Data-and-cloud-computing and technology are integral to the PCI-SIG consortium's development of PCIe 8.0. This technology employs optical interconnects and advanced packaging solutions like co-packaged optics and chiplet architectures with short-reach links, leveraging them to cater to the high-performance data throughput necessities in AI, data centers, and other high-end applications.

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