Side-by-Side Comparison
Optical Transceivers
QSFP28 vs. SFP28
Comparing 2 standards across 13 specifications. 13 key differences identified.
Comparing:
QSFP28
SFP28
QSFP28 (Quad Small Form-Factor Pluggable 28) is a 100 Gbps transceiver standard defined by SFF-8665 and IEEE 802.3bm. Integrating four 25 Gbps electrical lanes within the exact QSFP mechanical dimensions, it is the primary high-density interconnect for 100 Gigabit Ethernet and EDR InfiniBand.
SFP28 (25G Small Form-Factor Pluggable) is a transceiver standard defined under SFF-8402 and IEEE 802.3by. Using a single 25.78125 Gbps NRZ electrical lane within the standard SFP physical cage size, it provides high-density 25 Gigabit Ethernet and 32G Fibre Channel server-to-switch interconnects.
Specification Comparison Table
13 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard / MSA
|
SFF-8665 / SFF-8636 / IEEE 802.3bm | SFF-8402 / SFF-8432 / IEEE 802.3by |
|
Physical Form Factor
|
QSFP28 | SFP28 |
|
Electrical Channels
|
4 lanes @ 25.78125 Gbps NRZ | 1-lane (25.78125 Gbps NRZ) |
|
Max Data Rate (Ethernet)
|
103.125 Gbps | 25.78125 Gbps |
|
Max Data Rate (InfiniBand)
|
100 Gbps (EDR) | — |
|
Optical Connectors
|
MPO/MTP-12 (SR4, PSM4) or Duplex LC (CWDM4, LR4) | — |
|
4x25G Breakout Mode
|
Supported (to 4x SFP28 ports) | — |
|
Typical Power Consumption
|
3.5–5.0 W | — |
|
Max Data Rate (Fibre Channel)
|
— | 32 Gbps |
|
Optical Connector
|
— | Duplex LC |
|
Direct Attach Copper (DAC)
|
— | Up to 3m passive (5m with RS-FEC) |
|
Forward Error Correction (FEC)
|
— | Clause 74 (BASE-R) / Clause 108 (RS-FEC) |
|
Backward Compatibility
|
— | SFP+ (10 Gbps) in multi-rate ports |