{"product_id":"lmtqf022-sd-r-400g-qsfp112-passive-dac-stacking-cable-0-5m-nvidia-dgx-spark-validated-equivalent","title":"LMTQF022-SD-R 400G QSFP112 Passive DAC Stacking Cable, 0.5m – NVIDIA DGX Spark Validated Equivalent","description":"\u003cp\u003e\u003cstrong\u003eOEM-equivalent, DGX validated\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e LMTQF022-SD-R\u003cbr\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e 400G QSFP112 Passive Direct Attach Copper (DAC) Stacking Cable, 0.5m (1.6 ft)\u003c\/p\u003e\n\u003cp\u003eThe LMTQF022-SD-R is Luxshare's \u003cstrong\u003e400G QSFP112 passive DAC stacking cable\u003c\/strong\u003e engineered for the NVIDIA DGX Spark's \u003cstrong\u003ededicated stacking port\u003c\/strong\u003e. This is not the same cable used for standard 200G Ethernet networking — it connects to a separate, purpose-built port on the DGX Spark designed specifically for high-bandwidth, low-latency GPU-to-GPU communication when stacking two Spark units together. The LMTQF022-SD-R is NVIDIA's official part number for the Luxshare-manufactured version of this cable and is fully validated for DGX Spark stacking.\u003c\/p\u003e\n\u003cp\u003eUse the LMTQF022-SD-R when you need to stack two NVIDIA DGX Spark systems for up to 800GB\/s of combined memory bandwidth. Use the \u003ca href=\"\/products\/q56-200g-cu0-5-0-5-meter-1-6-ft-200g-qsfp56-passive-direct-attach-copper-dac-dgx-spark\"\u003eQ56-200G-CU0-5 200G QSFP56 DAC\u003c\/a\u003e for your ConnectX-7 NIC ports and standard 200G Ethernet networking.\u003c\/p\u003e\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003eLMTQF022-SD-R\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eLuxshare\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInterface\u003c\/td\u003e\n\u003ctd\u003eQSFP112\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eData Rate\u003c\/td\u003e\n\u003ctd\u003e400G (4 × 100G lanes)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCable Type\u003c\/td\u003e\n\u003ctd\u003ePassive Direct Attach Copper (DAC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLength\u003c\/td\u003e\n\u003ctd\u003e0.5 m (1.6 ft) \/ 400mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAWG\u003c\/td\u003e\n\u003ctd\u003e30AWG\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnector Type\u003c\/td\u003e\n\u003ctd\u003eQSFP112 on both ends\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePort Compatibility\u003c\/td\u003e\n\u003ctd\u003eNVIDIA DGX Spark dedicated stacking port only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUse Case\u003c\/td\u003e\n\u003ctd\u003eDGX Spark 2-unit stack configuration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProtocol\u003c\/td\u003e\n\u003ctd\u003eNVIDIA proprietary stacking link\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNVIDIA Validation\u003c\/td\u003e\n\u003ctd\u003eOfficially validated by NVIDIA for DGX Spark\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eWhat Port Does This Use?\u003c\/h2\u003e\n\u003cp\u003eThe DGX Spark has two distinct port types:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnectX-7 NIC ports (2×)\u003c\/strong\u003e — 200G QSFP56 — used for standard Ethernet networking. Compatible cable: \u003ca href=\"\/products\/q56-200g-cu0-5-0-5-meter-1-6-ft-200g-qsfp56-passive-direct-attach-copper-dac-dgx-spark\"\u003eQ56-200G-CU0-5\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDedicated Stacking port (1×)\u003c\/strong\u003e — QSFP112 — used exclusively for connecting two DGX Sparks together. Compatible cable: \u003cstrong\u003eLMTQF022-SD-R (this product)\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThese ports are not interchangeable. The stacking port only accepts QSFP112 connectors and only communicates with NVIDIA's proprietary stacking protocol.\u003c\/p\u003e\n\u003ch2\u003eImportant Limitations\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eOnly works between \u003cstrong\u003etwo DGX Spark units\u003c\/strong\u003e — cannot connect a DGX Spark to any other NVIDIA system or third-party device\u003c\/li\u003e\n\u003cli\u003eStacking is limited to \u003cstrong\u003e2 units maximum\u003c\/strong\u003e — you cannot chain more than 2 Sparks\u003c\/li\u003e\n\u003cli\u003eThe 0.5m length is the \u003cstrong\u003eonly supported length\u003c\/strong\u003e per NVIDIA's DGX Spark documentation — longer passive DAC cables are not certified\u003c\/li\u003e\n\u003cli\u003eDoes not add Ethernet networking capacity — for networking, use the ConnectX-7 ports with the Q56-200G-CU0-5\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eQuick Checklist — Is This the Right Cable?\u003c\/h2\u003e\n\u003cp\u003e✅ You have two NVIDIA DGX Spark units\u003cbr\u003e✅ You want to connect them via the dedicated stacking port\u003cbr\u003e✅ Your goal is expanded unified memory (up to 800GB\/s combined bandwidth)\u003cbr\u003e✅ You need a 0.5m passive copper cable with QSFP112 connectors on both ends\u003c\/p\u003e\n\u003cp\u003e❌ Do NOT use this cable for Ethernet networking — use the Q56-200G-CU0-5 for that\u003cbr\u003e❌ Do NOT use this cable to connect a DGX Spark to any switch or non-Spark device\u003cbr\u003e❌ Do NOT use this for connecting more than 2 DGX Spark units\u003c\/p\u003e\n\u003ch2\u003eRelated Guide\u003c\/h2\u003e\n\u003cp\u003eRead the full technical guide: \u003ca href=\"\/blogs\/news\"\u003eNVIDIA DGX Spark Stacking Cable: Amphenol NJAAKK-N911 vs Luxshare LMTQF022-SD-R — What's the Difference?\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003eAlso see: \u003ca href=\"\/products\/njaakk-n911-400g-qsfp112-passive-dac-stacking-cable-0-5m-nvidia-dgx-spark\"\u003eNJAAKK-N911 (Amphenol version)\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e📋 COMPATIBILITY DOCUMENTATION\u003c\/p\u003e\n  \u003cp\u003e \u003c\/p\u003e\n  \u003cp\u003eDownload comprehensive compatibility report: \u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0767\/3482\/4548\/files\/NJAAKK-N911_Compatibility_Report_bedab52f-2d7c-4b5a-8af1-10549419e7ab.pdf?v=1782784510\"\u003eNJAAKK-N911_Compatibility_Report\u003c\/a\u003e\u003c\/p\u003e\n  \u003cp\u003e \u003c\/p\u003e\n  \u003cp\u003eGuide includes: Pre-tested compatibility matrix for NVIDIA DGX Spark platforms, ConnectX-7 200GbE port verification, EEPROM data and recognition protocols, QSFP56 MSA compliance guidelines, dual-system interconnect setup instructions.\u003c\/p\u003e","brand":"NVIDIA","offers":[{"title":"Default Title","offer_id":48640278888548,"sku":"LMTQF022-SD-R","price":187.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0767\/3482\/4548\/files\/Screenshot_2026-06-24_102744.png?v=1782311353","url":"https:\/\/resilient-tec.com\/products\/lmtqf022-sd-r-400g-qsfp112-passive-dac-stacking-cable-0-5m-nvidia-dgx-spark-validated-equivalent","provider":"Resilient Tec","version":"1.0","type":"link"}