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400G QSFP-DD SR4
400G Optical Transceiver

400G QSFP-DD SR4

SKU / P/N: PHOS-4Q2FMS450M121
400G SR4 optical transceiver for AI data center, GPU cluster, reseller and system-integrator projects.
Data Rate
425Gbps
Form Factor
single-port QSFP-DD
Standard
SR4
Reach
40m @ OM3 / 70m @ OM4
Connector
MPO-12/APC
Max Power
8W
Spot Available Lead time: 2–4 weeks
Bulk package:
Custom Quote
Custom bulk order? Beyond 2000 pcs, mixed models or annual supply — use Custom Quote to negotiate your discount offline.

Bulk availability changes frequently. Discounts shown are indicative volume tiers — submit an RFQ to confirm the latest price, lead time and allocation. Prices are provided by quote — no public list price.

Link-up guaranteedCoded to any switch / NIC platform
Lifetime warrantyAdvance replacement
Ships from US warehouseFast, no import hassle
Per-unit testedTest report + power-on video

Product description

Generic-compatible 400GBASE-SR4 QSFP-DD PAM4 optical transceiver — multimode fiber, 850 nm, 50 m, MTP/MPO-12, DOM.

The 400GBASE-SR4 transceiver reaches up to 50 m over parallel OM4 multimode fiber through an MTP/MPO-12 connector, complying with IEEE 802.3df-2024 and the 400GAUI-8 standard.

The 400G Ethernet signal is transmitted over four parallel lanes, one wavelength per lane.

Product highlights

  • Integrated low-power DSP for stable performance at scale
  • Optimized power budget, max power consumption 8W
  • Compliant with QSFP-DD MSA and IEEE 802.3 standards
  • Supports breakout to lower-rate links for flexible fabric design
  • Backward compatible with existing QSFP form-factor ports
  • Tested on live switch / NIC platforms to ensure performance, quality and reliability

Applications

  • AI data center & GPU cluster interconnect
  • Spine-leaf switching fabric
  • Short-reach in-rack and adjacent-rack connections
  • Hyperscale, cloud and high-performance computing networks

Supply status meaning

In stock or short-notice availability

Data Rate425Gbps
Max Data Rate8x53.125Gbps
Form Factorsingle-port QSFP-DD
StandardSR4
Lanes8
Rate per Lane53.125Gbps PAM4
Reach40m@OM3 / 70m@OM4
MediaMMF
Fiber TypeOM3 / OM4
ConnectorMPO-12/APC
Connector PolishAPC
Wavelength850nm
Max Power8W
Operating Temperature0 to 70C (32 to 158F)
Optical Modulation4x100G-PAM4
Electrical Modulation8x50G-PAM4
FECInbuilt FEC: Yes
IEEE ComplianceIEEE 802.3
MSA ComplianceQSFP-DD MSA
ProtocolsQSFP-DD MSA,IEEE 802.3,CMIS5.2
Host Interfacesingle-port QSFP-DD
Warranty5

Four bulk tiers — the larger the volume, the better the discount. Actual pricing is confirmed by RFQ based on quantity, customer tier and lead time; there is no single-unit retail.

PackageQuantityVolume discountBest for
Starter Pack 100 pcs Base bulk price Trial order / small channel Request Quote
Growth Pack 500 pcs Save ~5% vs. Starter Reseller / regular supply Request Quote
Project Pack Popular 1000 pcs Save ~10% vs. Starter AI data center project Request Quote
Strategic Pack 2000 pcs Save ~15% vs. Starter Annual / channel agreement Request Quote
Custom bulk order 2000+ pcs Negotiated offline Annual / strategic supply Contact Sales

Ask a compatibility question

Need this model to match a specific switch, NIC or OEM coding? Send us the platform and we'll confirm compatibility and coding options.

  • Compatible coding for major switch / NIC platforms on request
  • Alternative model recommendations
  • Breakout and cabling guidance

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