Most of today’s large data centers use 100Gbps Ethernet infrastructure to move data over long distances (e.g., between racks and data centers). Long-reach infrastructures typically rely on 4 channels of 25 or 28 Gbps NRZ SerDes electrical connectivity. However, as data volume grows, higher speed infrastructure is needed to sustain data movement. Using 56 and 112 Gbps SerDes IP that supports PAM-4 encoding enables 400Gbps Ethernet connectivity in hyperscale data centers being deployed today, as well as speeds up to 800Gbps in the future (Figure 2). Leading Ethernet switch vendors are already developing 800Gbps switches based on 112G SerDes IP, with plans to introduce 1.6Tbps Ethernet (using a faster, next-generation SerDes) within the next few years to meet the demands of increasing data volumes.
Data communication between servers within a rack is managed by the Top-of-Rack (ToR) switch and network interface cards (NICs) within each server. The most common interface speed in cloud data centers at this level has been 25Gbps for the past few years. However, as infrastructure speeds increase to 400Gbps, Ethernet speed within the rack is increasing to 100Gbps.
With data rates increases, interface power (typically measured in picoJoules/bit) and area become increasingly important. Physical interface (PHY) IP that minimizes energy use while delivering data reliably across required distances has distinct advantages for minimizing the cost of infrastructure power and cooling capacity. Silicon area-efficient PHY solutions minimize SoC cost, which improves profitability for the SoC vendor.