Built to scale data centre compute fabrics inside accelerated servers, general-purpose servers, CXL systems and disaggregated infrastructure, the first two products, 8- and 16-lane PCIe Gen 6 retimers, connect AI accelerators, GPUs, CPUs and other components inside server systems.
Artificial intelligence (AI) and machine learning (ML) applications are driving data flows and connections inside server systems at significantly higher bandwidth, which means that PCIe retimers have to meet the required connection distances at faster speeds. PCIe is the industry standard for inside-server-system connections between AI accelerators, GPUs, CPUs and other server components.
AI models are doubling their computation requirements every six months and are now the primary driver of the PCIe roadmap, with PCIe Gen 6 becoming a requirement.
PCIe Gen 6, which operates at 64 gigatransfers-per-second (GT/s), is the first PCIe standard to use four-level pulse-amplitude modulation (PAM4) signalling, displacing the non-return to zero (NRZ) modulation used for the last 20 years.
The higher bandwidth and faster data rate limit the physical reach signals can travel reliably, reducing the distance connections can span. Marvell’s Alaska P retimers look to address this by compensating for the signal degradations and regenerating the signal to deliver reliable communication over the physical distances required for connections between GPUs and CPUs within an AI server, between GPUs on different boards, or between CPUs and a pool of shared memory enabled by CXL, among other use cases.
The retimers can be used on AI accelerator baseboards, server motherboards, riser cards, or integrated into active electrical cables (PCIe AEC) and active optical cables (PCIe AOC) for emerging multi-rack server system architectures.
“Signal distance is a real dilemma for service providers. We estimate over 75% of cloud and AI servers shipping two years from now will rely on retimers and these servers will contain multiple retimers. An eight GPU server might contain 16 or more of these devices. Retimers will even percolate into enterprise servers,” said Alan Weckel, co-founder of 650 Group. “Marvell’s extensive experience in PAM4 technology positions the company well to drive the evolution of this emerging market.”
The new Alaska P PCIe retimer product line extends Marvell’s PAM4 connectivity portfolio beyond Ethernet and InfiniBand interconnects into copper and optical PCIe, CXL and proprietary compute fabric links. The product line addresses connections inside AI and general-purpose server systems, expanding the addressable market for Marvell.
With typical power consumption of 10 watts, the 5nm 16-lane PCIe 6 retimer operates at what is said to be the lowest power in the industry today. Available in 8- and 16-lane configurations, the Alaska P PCIe devices can compensate for 40dB of channel loss compared to the spec of 32dB at PCIe 6.
The retimers can be used for on-board or cable copper connections or combined with electrical-to-optical components to produce optical PCIe modules, addressing different cloud customer data center architectures. Marvell is working with cable and optical module partners to integrate the products into cloud-optimized interconnect solutions for different data center customer applications.
Key features include:
- Compatible with PCI Express Gen 6/5/4/3/2/1 and Compute Express Link 3/2/1.1
- Industry-leading PAM4 SerDes performance
- Low-latency mode for cache-coherent links
- Industry’s lowest power consumption (10W PCIe 6 x16)
- Industry-standard x16 and x8 footprints
- Advanced telemetry and diagnostics: in-band FEC monitoring, out-of-band SerDes eye monitoring, embedded logic analyser and software suite for fleet management in large-scale deployments
“We are now entering the market for compute fabrics as PCIe and CXL go through an inflection point, migrating from NRZ to PAM4 technology,” said Venu Balasubramonian, vice president of product marketing, Connectivity Business Unit at Marvell. “Marvell is building on more than 10 years of in-house expertise in PAM4 technology and our industry-leading 5nm PAM4 IP portfolio to enable this transition. Our Alaska P PCIe retimer family is an important addition to the comprehensive Marvell accelerated infrastructure portfolio.”
