QSFP-DD vs. SFP+
Comparing 2 standards across 14 specifications. 14 key differences identified.
Quad Small Form-Factor Pluggable Double Density (QSFP-DD) is a high-speed transceiver form factor defined by the QSFP-DD MSA and SFF-TA-1002. It incorporates an 8-lane electrical interface via an extra row of electrical contacts, delivering 400 Gbps (8x50G PAM4) and 800 Gbps (8x100G PAM4) while maintaining mechanical backward compatibility with QSFP28 and QSFP+.
Enhanced Small Form-Factor Pluggable (SFP+) is a standardized 10 Gbps transceiver form factor defined by SFF-8431 and SFF-8432. Retaining the physical dimensions of standard SFP, it supports 10 Gigabit Ethernet (10GbE), 8G/16G Fibre Channel, and OTU2 over a single 10.3125 Gbps serial electrical lane.
Specification Comparison Table
14 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard / MSA
|
QSFP-DD MSA / SFF-TA-1002 | SFF-8431 / SFF-8432 |
|
Physical Form Factor
|
QSFP-DD (Double Density) | SFP+ (Enhanced SFP) |
|
Electrical Channels
|
8 lanes (via dual-row contact pins) | 1-lane (10.3125 Gbps NRZ) |
|
Backward Compatibility
|
Accepts QSFP+, QSFP28, and QSFP56 modules | Accepts 1G SFP in dual-rate ports |
|
Max Data Rate (400G Generation)
|
400 Gbps (8x50G PAM4) | — |
|
Max Data Rate (800G Generation)
|
800 Gbps (8x100G PAM4) | — |
|
Optical Connectors
|
MPO/MTP-16, Dual MPO-12, Duplex LC, CS, SN, MDC | — |
|
Electrical Modulation
|
PAM4 (4-level Pulse Amplitude Modulation) | — |
|
Thermal Power Dissipation
|
Up to 12–25 W | — |
|
Max Data Rate (Ethernet)
|
— | 10.3125 Gbps |
|
Max Data Rate (Fibre Channel)
|
— | 16 Gbps |
|
Optical Connector
|
— | Duplex LC |
|
Direct Attach Copper (DAC)
|
— | Supported (Twinax up to 7m passive) |
|
Digital Optical Monitoring (DOM)
|
— | SFF-8472 standard |