The QSFP-DD (Quad Small Form Factor Pluggable Double Density) module is a high-speed, high-density transceiver module used in data center and networking applications. The QSFP-DD module has a larger form factor compared to the traditional QSFP module, as it is designed to support double the data rate and density. The QSFP-DD module has eight electrical lanes, each operating at 25 Gbps or 50 Gbps, resulting in a total data rate of 200 Gbps or 400 Gbps.

The physical size of a QSFP-DD module is larger than that of a standard QSFP module. The dimensions of a QSFP-DD module are approximately 18.35 mm in width, 72.71 mm in length, and 8.5 mm in height. This larger form factor allows for additional electrical lanes and higher data rates, making QSFP-DD suitable for high-speed applications in modern data center environments.

400G QSFP-DD LR4

Product Features⚫ Supports 425Gb/s bit rate ⚫ Hot Pluggable QSFP-DD form factor ⚫ Support Digital Monitoring interface ⚫ Compliant to QSFP-DD Rev 4.0 ⚫ SFF-8636 Management Interface ⚫ SFF-8679: General Electrical ⚫ IEEE 802.3cd: Physical Layer Specifications and Management Parameters ⚫ All-metal housing for superior EMI performance ⚫ Meet ESD requirements, resist 8KV direct contact voltage ⚫ RoHS-10 compliant and lead-free ⚫ Single +3.3V power supply ⚫ Case operating temperature: 0°C to +70°C

It's worth noting that while the physical size of the QSFP-DD module is larger, the form factor is designed to maintain compatibility with QSFP and QSFP28 ports, enabling backward compatibility with existing infrastructure while providing higher data rates for next-generation networking equipment.