QNAP QXG-25G2SF-BCM Dual-Port 25GbE PCIe 4.0 Network Expansion Card
Overview
The QXG-25G2SF-BCM is a dual-port 25 GbE network expansion card built on the Broadcom BCM57504 controller. It slots into a PCIe 4.0 host and delivers up to 50 Gbps aggregate throughput — enough bandwidth to eliminate NAS-to-switch bottlenecks when running parallel high-throughput workloads such as 4K/8K video editing over SMB, large-dataset backup streams, or multi-initiator iSCSI configurations. Both ports use SFP28 connectors, supporting direct-attach copper (DAC) cables or optical transceivers for flexible cabling in rack or tower deployments. PCIe 4.0 compatibility means the card won't be bandwidth-constrained at the host interface even when both ports run at line rate simultaneously — a meaningful factor for QNAP NAS units with PCIe 4.0 expansion slots.
Compatibility
The QXG-25G2SF-BCM is designed to install in QNAP NAS enclosures and servers that provide a PCIe 4.0 (or backward-compatible PCIe 3.0) x8 or x16 slot with PCIe expansion support. Compatible QNAP families include the TVS-h series (e.g., TVS-h877AX, TVS-h1288X), TDS-h series, and TS-h series high-performance NAS units with PCIe expansion bays. Verify your specific QNAP model's PCIe slot generation and physical slot width before ordering — a PCIe 3.0 host will accept the card but cap bandwidth accordingly. The SFP28 interface is compatible with 25GbE SFP28 DAC cables, active optical cables, and SFP28 transceivers from major vendors; it also supports fallback to 10GbE SFP+ devices depending on switch and transceiver negotiation.
Installation Notes
Install requires powering down the NAS, seating the card in a compatible PCIe slot, and securing with the standard PCIe bracket screw. Ensure your 25GbE switch or upstream port supports SFP28 at matching speed. DAC cable length limits apply per vendor spec — passive DAC typically reaches 3–5 meters; active DAC or optical extends further for cross-rack runs. No additional power connector is required beyond the PCIe slot itself.
