400G QSFP-DD To 4 x 100G QSFP56 DAC meets the SFF-8636 and QSFP-DD multi-source protocol standards. The QSFP-DD has an 8-channel electrical interface for data transfer rates up to 28Gbps NRZ or 56Gbps PAM4, and total data rates up to 200Gbps or 400Gbps.