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Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →The Intel SPTSLP2SLCDF is a 100G DR QSFP28 optical transceiver specified for 500 m over single-mode fiber with an LC connector. Its interesting detail is the lane conversion reported in ServeTheHome’s teardown: four 25G NRZ electrical lanes become one 100G PAM4 optical lane.
What the SPTSLP2SLCDF is
Intel’s product brief identifies the SPTSLP2SLCDF as a 100G DR QSFP28 transceiver with an LC optical connector and a specified reach of 500 m over single-mode fiber. The product name also identifies it as a 1311 nm module. See Intel’s 100G DR/FR/LR product brief for the product-family context.
“QSFP28” describes the module form factor and host-side interface; it does not mean the optical signal uses four separate 25G lanes. In its inspection, ServeTheHome describes NRZ signaling on the QSFP28 electrical side and PAM4 on the optical side. It reports that an Inphi IN010C25 Alcor DSP inside the module performs the conversion from four 25G NRZ electrical lanes to one 100G PAM4 optical lane. This is a teardown observation reported by ServeTheHome, not an independently repeated measurement or a separately confirmed Intel bill of materials. ServeTheHome’s inspection identifies the chip as an Inphi part and notes that Inphi was acquired by Marvell.
Why the electrical-to-optical conversion matters
The module bridges two different lane arrangements: four electrical lanes at the QSFP28 interface and a single PAM4 optical lane. PAM4 represents more than one bit per signaling symbol, allowing the optical side to carry the required data rate on one lane. The DSP is therefore central to how this optic accepts the host-side signaling arrangement and produces its optical output.
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- The 100GbE QSFP28 module provides 100GBase-LR4 throughput up to 10km over a standard pair of single mode fiber (SMF) with duplex LC connectors.
- Data Rare: 100Gbps. Connector: Duplex LC. Transmitter Type: 4 x LAN WDM EML. Support 100G to 4x25G Breakout Application.
- Hot Pluggable QSFP28 MSA Compliant. With DDM Function to monitor real-time parameter and state on fiber links.
- Compliant with IEEE 802.3 100GBASE-LR4, SFF-8665 and SFF-8636 standards. Digital diagnostics functions are also available via the I2C interface, as specified by the QSFP28 MSA, to allow access to real-time operating parameters.
- Compatible with Arista SFP-100G-LR4/Brocade SFP-100G-LR4/Dell SFP-100G-LR4/Intel E810/Mellanox MMA1B00-C100D/Palo Alto Networks PAN-100G-QSFP28-LR4 and other fiber switches, routers, NIC, server or other fiber optic equipment with 100G QSFP28 ports.
This distinction is useful when assessing an optic or diagnosing a link: the host interface and the fiber-facing signal are not necessarily organized into matching numbers of lanes. The conversion described here is specific to the teardown of this module; it should not be assumed to describe every QSFP28 optic.
How DR compares with Intel’s FR and LR variants
Intel’s family specification page lists DR, FR, and LR variants with different stated reaches. The exact SPTSLP2SLCDF product brief identifies the DR version as 500 m; do not substitute the reach of a sibling SKU.
Rank #2
- 100GBASE-SR4 QSFP28 to MPO Optical 100G Ethernet transceiver module, Multimode, 850nm, MPO/MTP connector, DDM, up to 70-Meter on OM3, up to 100-Meter on OM4.
- Wide Compatibility - Compatible for Cisco QSFP-100G-SR4-S and Other Open Switches.
- Easy to Use - Easy installation, plug and play, fully hot-pluggable. Widely used in fiber switches, routers, NIC, server or other fiber optic equipments with 100Gb QSFP28 ports.
- Superior DDM Function - DDM allows you to monitor the critical information concerning the status of the transmitted and received signals of the transceivers in real-time to find out some potential problems.
- 10Gtek is a manufacturer of transceivers, customized service is available.
| Intel family variant | Specified reach | What to verify |
|---|---|---|
| DR | 500 m, as specified for the SPTSLP2SLCDF in Intel’s product brief | Confirm the complete part number, fiber plant, and host-platform support. |
| FR | 2 km, listed on Intel’s family specification page | Confirm the exact FR SKU and its product documentation; this is not the reach of the DR part. |
| LR | 10 km, listed on Intel’s family specification page | Confirm the exact LR SKU and its product documentation; this is not the reach of the DR part. |
Choose by required distance and the installed optical infrastructure, then check the exact module SKU against the switch or other host’s supported optics. A shared QSFP28 shape does not guarantee that a host will accept or operate with a particular module.
Connector, fiber, and compatibility checks
The documented optical interface for the SPTSLP2SLCDF is LC over single-mode fiber. Intel’s product brief describes the family’s use of single-mode fiber infrastructure, while ServeTheHome also describes an LC connector. A third-party description of 100GBASE-DR category optics likewise gives the category context as one 1310 nm PAM4 optical lane over duplex single-mode fiber for up to 500 m; that does not establish Intel-specific compatibility. EDGE Optical Solutions’ category description is not a substitute for the module’s own documentation.
Rank #3
- HIGH-SPEED 100G CONNECTIVITY - Supports a maximum data rate of 103.125Gbps through 4 x 25.78Gbps lanes, providing high-bandwidth connectivity for data centers, enterprise infrastructure, server interconnects and high-performance computing.
- INTEL COMPATIBLE OPTICAL MODULE - Designed for compatibility with Intel network equipment using supported 100G QSFP28 interfaces. Please verify your exact host model, port specification and transceiver requirements before installation.
- 850NM MTP/MPO-12 INTERFACE - Features an 850nm VCSEL transmitter, PIN receiver and MTP/MPO-12 optical interface for multimode fiber connectivity. Designed for 100GBASE-SR4 short-reach Ethernet applications.
- 70M OM3 OR 100M OM4 REACH - Supports transmission distances of up to 70m over OM3 and 100m over OM4 multimode fiber, making it suitable for high-density data center and short-distance network deployments.
- DDM/DOM MONITORING & STABLE OPERATION - Supports DDM/DOM monitoring and built-in TX/RX CDR. With typical power consumption of ≤2.5W and a 0°C to 70°C operating range, it is suitable for standard commercial network environments.
- Part number: Match the complete SPTSLP2SLCDF identifier, not an Intel FR or LR sibling.
- Host support: Check the equipment vendor’s supported-transceiver list and any module coding requirements.
- Optical path: Confirm that the link design, single-mode fiber, connectors, and total path loss are appropriate for the intended distance.
- Patch cable: The cited sources do not establish an exact cable length. Select cable type and length for the actual fiber route and link design, and confirm requirements with the equipment vendor.
Intel’s family specification page lists IEEE 100GBASE-DR and 100G Lambda MSA compliance, FEC support, maximum power of 4.5 W, an operating temperature range of 0–70°C, and SFF-8636 I²C diagnostics. Because that page covers the DR/FR/LR family, verify the precise feature and operating requirements in documentation for the exact SKU before treating every family-level item as confirmed for the SPTSLP2SLCDF.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What ServeTheHome’s quick look adds
In the article dated February 20, 2026, ServeTheHome author Patrick Kennedy says the publication bought 40 modules for a particular application, needed 32, and sacrificed one for the teardown. Those figures describe that specific purchase and inspection; they do not establish general market availability or demand.
Rank #4
- 100GBASE-ER4 QSFP28 Optical Transceiver Module, Built-in high performance Chip, Max. Power Consumption 4.5W enable Prolonged Service Life. with BOX Packaging, it enable Great Reliability, and Heat Dissipation Performance
- Tested in Targeted Switches for Superior Performance, Quality, and Reliability. We owns compatibility LAB facilities to meet the EEPROM coding and writing requirements with various brands of the latest and advanced networking equipments to ensure the reliability.
- Built-in Real Time Digital Optical Monitoring Capability for Strong Diagnostic Capabilities.
- Hot Pluggable QSFP28 MSA and RoHS-6 Compliant to Maximize Uptime and Simplify Maintenance
- High-Speed 4x25G Electrical Interface Compliant to IEEE 802.3ba 100GBASE ER4
Kennedy’s advice is deliberately narrow: “These are fairly specific tools and generally, we would not suggest getting DR1 optics unless you need them.” It is editorial guidance in the context of the article, not a universal compatibility rule or a claim that the module is unsuitable for its intended application.
Quick Recap
Best Value
- 100GBASE-SR4 QSFP28 to MPO Optical 100G Ethernet transceiver module, Multimode, 850nm, MPO/MTP connector, DDM, up to 70-Meter on OM3, up to 100-Meter on OM4.
- Wide Compatibility - Compatible for Cisco QSFP-100G-SR4-S and Other Open Switches.
- Easy to Use - Easy installation, plug and play, fully hot-pluggable. Widely used in fiber switches, routers, NIC, server or other fiber optic equipments with 100Gb QSFP28 ports.
- Superior DDM Function - DDM allows you to monitor the critical information concerning the status of the transmitted and received signals of the transceivers in real-time to find out some potential problems.
- 10Gtek is a manufacturer of transceivers, customized service is available.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
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