Marvell revs up Ethernet to 400Gbps with new ‘Alaska’ chips

Marvell Semiconductor is the first semiconductor to ship networking chips supporting the 802.3cd standard that will pump up Ethernet ports to 400Gbps max.

The 802.3cd standard is designed to eventually replace the current physical Ethernet ports, which run at 25Gbps to 100Gpbs, with ports that will run at 50Gbps, 200Gbps, and 400Gbps.

And Marvell is the first chip vendor out of the gate with support for the standard in its Alaska C 88X7120 transceivers. The chips aren’t fully cooked, but they are sampling to customers. Sampling is to semiconductors what beta testing is to software.

The chips support 16 50Gbps ports, four 200Gbps ports, and two 400Gbps ports, using PAM4 signaling. They’re aimed at top-of-rack switches with interfaces ranging from 25Gbps to 400Gbps.

PAM4 stands for pulse-amplitude modulation, a four-level signaling technique designed to replace the non-return to zero (NRZ) binary modulation. It has long been thought to be the way to get to 400Gbps throughput, and now Marvell says it can do it. Although PAM4 is a a newer protocol, devices using it will be backwards-compatible with NRZ hardware.

The port density on the 88X7120 has been specifically optimized to enable QSFP-DD (Quad Small Form Factor Pluggable – Double Density) and OSFP (Octal Small Form Factor Pluggable) port types for 50GbE, 200GbE, and 400GbE deployments. OSFP is an eight-lane port spec designed to address the higher power dissipation needed for 400Gbps.

The chips also support both copper and fiber-optic wiring, as well as long-reach serialisation/deserialisation (SerDes) on system and line side interfaces, the company said, so OEMs can use the chips for wide-area interfaces.

Marvell is targeting hyperscale data centers, where throughput is most urgently needed. It expects to begin shipping final product in 2019.