Wednesday, November 4, 2020

Spectra7 Sets Sights on 56Gbps PAM4 NIC designs


Spectra7 Microsystem announced three new reference designs targeted at new server connectivity needs implementing 56Gbps PAM4 signaling on Ethernet Network Interface Cards (NICs). 

As servers adopt higher bandwidth ports that utilize 56Gbps PAM4 signaling, passive cables cannot serve all lengths needed. Instead of deploying optical interconnects that are much higher power and more costly, operators are looking to Active Copper Cables (ACCs) to serve this growing need. One example is Tencent who demonstrated a Spectra7 enabled ACC for server connectivity in September at China’s Open Data Center Committee (ODCC) conference. The 200Gbps demonstration showed a Spectra7 enabled ACC “splitter cable” connecting from a 200Gbps top-of-rack (ToR) switch port to 2 separate servers with 100Gbps NIC ports. The signaling in the cable was 56Gbps PAM4. This “splitter cable” architecture is being widely planned both in the US and in China for next generation deployments.

GCS-QSFP Reference Design

Server Connectivity Splitter Cable with 200Gbps QSFP56-CR4 form factor module at switch end and 2 QSFP56-CR2 form factor modules at server ends. A total of 4 GC2502 ICs are used in this reference design.

GCS-DSFP Reference Design

Server Connectivity Splitter Cable with 200Gbps QSFP56-CR4 form factor module at switch end and 2 DSFP-CR2 form factor modules at server ends. A total of 4 GC2502 ICs are used in this reference design.

GCS-SFP-DD Reference Design

Server Connectivity Splitter Cable with 200Gbps QSFP56-CR4 form factor module at switch end and 2 SFP-DD-CR2 form factor modules at server ends. A total of 4 GC2502 ICs are used in this reference design.

http://www.spectra7.com/pam4-referencedesigns