{"product_id":"mellanox-qm9790-ns2f-400g-ndr-infiniband-switch-64-port-used","title":"Mellanox QM9790-NS2F 400Gb\/s NDR InfiniBand Switch 64-Port Used","description":"\u003cp style=\"margin:14px 0 18px;padding:12px 16px;background:#f4f7fb;color:#1a1a1a;border-radius:6px;font-size:15px;line-height:1.6;\"\u003e\u003cstrong\u003eQuick answer:\u003c\/strong\u003e NVIDIA Quantum-2 QM9790 MQM9790-NS2F used, bench-tested. NVIDIA Quantum-2 QM9790 with 64 NDR 400Gb\/s ports on 32 OSFP cages, 51.2 Tb\/s bidirectional, 1U, P2C airflow, and no on-board subnet manager — the fabric is driven by UFM or OpenSM from a host.\u003c\/p\u003e\n\u003cp style=\"margin:0 0 10px;padding:12px 16px;background:#eef8ef;border-left:4px solid #2e7d32;color:#1a1a1a;border-radius:4px;font-size:15px;line-height:1.6;\"\u003e\u003cstrong\u003eIn stock:\u003c\/strong\u003e MQM9790-NS2F is in stock — availability is confirmed per part number, so send the exact model you need and we check the shelf before quoting.\u003c\/p\u003e\n\u003cp style=\"margin:0 0 18px;padding:12px 16px;background:#f7f9fc;border:1px solid #dde5ef;border-radius:6px;font-size:15px;line-height:1.6;\"\u003e\u003cstrong\u003eNeed a quote?\u003c\/strong\u003e Message WhatsApp \u003ca href=\"https:\/\/wa.me\/8613068616914\"\u003e+86 13068616914\u003c\/a\u003e with the part number (for example MQM9790-NS2F) and the quantity — we reply with price, condition notes and photos of the actual unit. No price is listed here because every order is quoted per part number.\u003c\/p\u003e\n\u003ch2\u003eNVIDIA Quantum-2 QM9790\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eNVIDIA Quantum-2 QM9790\u003c\/strong\u003e is the externally managed member of the QM9700 series: 64 non-blocking NDR 400Gb\/s InfiniBand ports on 32 OSFP cages in a 1U chassis, 51.2 Tb\/s of bidirectional bandwidth, and in-network computing through SHARPv3. Because the subnet manager lives outside the switch, one UFM or OpenSM instance can drive a whole fabric instead of one manager per box.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eCondition: Used — cleaned, re-flashed and bench-tested on our own test line before it is listed. 90-day warranty from delivery.\u003c\/em\u003e\u003c\/p\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;margin:12px 0;font-size:14px;\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"background:#f8f9fa;padding:8px;border:1px solid #dee2e6;width:32%;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"background:#f8f9fa;padding:8px;border:1px solid #dee2e6;\"\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePart number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eMQM9790-NS2F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFamily\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eNVIDIA Quantum-2 QM9790\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSwitch silicon\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eNVIDIA Quantum-2 (switch IC for NDR 400Gb\/s InfiniBand)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePorts\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e64 × 400Gb\/s NDR, 32 OSFP cages; up to 128 × 200Gb\/s with splitters\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePort speed\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e400Gb\/s NDR per port (200Gb\/s per port with 2-way split)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eConnectors\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eOSFP (32 cages, 64 ports)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSwitching capacity\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e51.2 Tb\/s bidirectional, non-blocking\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePacket buffer\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eShared buffer with adaptive routing and congestion control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eAirflow\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eP2C — power-to-connector (front-to-back)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eForm factor\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1U rackmount\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e43.6 × 438 × 660 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePower\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e2 × hot-swap PSU (1+1), 200-240 VAC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eManagement\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eExternally managed — subnet manager runs on a host (OpenSM) or NVIDIA UFM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSoftware\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eNVIDIA UFM \/ MLNX-OS fabric software\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eKey features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e64 × NDR 400Gb\/s non-blocking ports on 32 OSFP cages\u003c\/li\u003e\n\u003cli\u003eUp to 128 × 200Gb\/s ports using 2-way port splitting\u003c\/li\u003e\n\u003cli\u003eSHARPv3 in-network aggregation for collective operations\u003c\/li\u003e\n\u003cli\u003eAdaptive routing and congestion control for lossless fabrics\u003c\/li\u003e\n\u003cli\u003eBackward compatible with HDR 200G, EDR 100G and FDR links\u003c\/li\u003e\n\u003cli\u003eFat tree, DragonFly+, SlimFly and multi-dimensional torus topologies\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTypical deployments\u003c\/h3\u003e\u003cp\u003eGPU training clusters, HPC fabrics, storage backbones for Lustre and GPFS, and super-spine layers where central UFM telemetry is preferred over per-switch management.\u003c\/p\u003e\n\u003ch3\u003eWhat is included\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eSwitch chassis with both power supplies\u003c\/li\u003e\n\u003cli\u003eFan units as configured for P2C airflow\u003c\/li\u003e\n\u003cli\u003eRack mounting kit\u003c\/li\u003e\n\u003cli\u003eCondition report and bench-test notes for the unit you receive\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eNot included\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eOSFP transceivers and cables\u003c\/li\u003e\n\u003cli\u003eSubnet manager licence (UFM) or OpenSM host\u003c\/li\u003e\n\u003cli\u003eRails for non-standard racks\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eMQM9790-NS2F in the lineup\u003c\/h3\u003e\u003cp\u003eWithin the QM9700 series the difference is management, not bandwidth: QM9700 carries an on-board subnet manager for fabrics up to about 2,000 nodes, while QM9790 leaves the manager external so a single UFM instance can cover a larger fabric with one consistent telemetry view. Ports, speed and airflow options are the same.\u003c\/p\u003e\n\u003ch3\u003eHow it compares with models we also stock\u003c\/h3\u003e\u003ctable style=\"width:100%;border-collapse:collapse;margin:12px 0;font-size:14px;\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"background:#f8f9fa;padding:8px;border:1px solid #dee2e6;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"background:#f8f9fa;padding:8px;border:1px solid #dee2e6;\"\u003eFabric\u003c\/th\u003e\n\u003cth style=\"background:#f8f9fa;padding:8px;border:1px solid #dee2e6;\"\u003ePorts\u003c\/th\u003e\n\u003cth style=\"background:#f8f9fa;padding:8px;border:1px solid #dee2e6;\"\u003eBest for\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#fbfdff;font-weight:600;\"\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003eMQM9790-NS2F\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003eInfiniBand NDR 400G\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003e64 (32 OSFP)\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003eLarge fabrics run from UFM\/OpenSM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003eMQM9700-NS2F\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003eInfiniBand NDR 400G\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003e64 (32 OSFP)\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003eStandalone fabrics up to ~2,000 nodes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003eMSB7700-ES2F\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003eInfiniBand EDR 100G\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003e36 QSFP28\u003c\/td\u003e\n\u003ctd style=\"padding:8px;border:1px solid #dee2e6;\"\u003eEDR estates and mixed-generation fabrics\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eWhy buy this switch from Zhongxin Data\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eBench-tested on our own in-house test line — ports, fans and power supplies are checked before the unit leaves.\u003c\/li\u003e\n\u003cli\u003eWe quote only what we can physically confirm: the exact part number, airflow direction and condition notes come from the unit in front of us.\u003c\/li\u003e\n\u003cli\u003eUsed enterprise switches at secondary-market pricing, with a 90-day warranty from delivery.\u003c\/li\u003e\n\u003cli\u003eWorldwide shipping from Hong Kong, China; consolidation with servers, NICs and optics from the same rack is routine.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eRequest a quote\u003c\/h3\u003e\u003cp\u003eSend the part number \u003cstrong\u003eMQM9790-NS2F\u003c\/strong\u003e, the quantity you need and your destination to WhatsApp \u003ca href=\"https:\/\/wa.me\/8613068616914\"\u003e+86 13068616914\u003c\/a\u003e (or reply to any thread on zhongxindata.hk). We confirm availability against the exact model before quoting, and we can quote alternative airflow builds or port-count variants from the same family if they fit your rack better.\u003c\/p\u003e\n\u003ch3\u003eFrequently asked questions\u003c\/h3\u003e\n\u003cdetails style=\"margin:8px 0;padding:8px;border:1px solid #e0e0e0;border-radius:4px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;color:#1a1a1a;\"\u003eWhat is the difference between QM9790 and QM9700?\u003c\/summary\u003e\u003cp style=\"margin:8px 0 0;color:#444;\"\u003eManagement. QM9790 has no on-board subnet manager, so UFM or OpenSM runs on a host. QM9700 includes an on-board subnet manager for fabrics up to roughly 2,000 nodes. Ports, speed and airflow are the same.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails style=\"margin:8px 0;padding:8px;border:1px solid #e0e0e0;border-radius:4px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;color:#1a1a1a;\"\u003eIs this switch managed or unmanaged?\u003c\/summary\u003e\u003cp style=\"margin:8px 0 0;color:#444;\"\u003eIt is externally managed. The chassis boots as a fabric device and relies on an external subnet manager; plan for UFM or an OpenSM host before you deploy it.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails style=\"margin:8px 0;padding:8px;border:1px solid #e0e0e0;border-radius:4px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;color:#1a1a1a;\"\u003eWhat does NS2F mean?\u003c\/summary\u003e\u003cp style=\"margin:8px 0 0;color:#444;\"\u003eN for NDR, S2 for the standard-depth 1U chassis, F for power-to-connector (front-to-back) airflow. The reverse-airflow version is NS2R.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails style=\"margin:8px 0;padding:8px;border:1px solid #e0e0e0;border-radius:4px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;color:#1a1a1a;\"\u003eCan I run 200Gb\/s ports on it?\u003c\/summary\u003e\u003cp style=\"margin:8px 0 0;color:#444;\"\u003eYes. Each 400Gb\/s port splits two ways, giving up to 128 ports of 200Gb\/s with the right cables.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails style=\"margin:8px 0;padding:8px;border:1px solid #e0e0e0;border-radius:4px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;color:#1a1a1a;\"\u003eDoes it work with HDR or EDR adapters?\u003c\/summary\u003e\u003cp style=\"margin:8px 0 0;color:#444;\"\u003eYes. The Quantum-2 platform negotiates down to HDR 200G, EDR 100G and FDR, so mixed-generation fabrics work at the speed of the slower link.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails style=\"margin:8px 0;padding:8px;border:1px solid #e0e0e0;border-radius:4px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;color:#1a1a1a;\"\u003eIs it Ethernet or InfiniBand?\u003c\/summary\u003e\u003cp style=\"margin:8px 0 0;color:#444;\"\u003eInfiniBand. This is a Quantum-2 fabric switch for native IB verbs. For RoCEv2 over Ethernet, look at the Spectrum SN series instead.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails style=\"margin:8px 0;padding:8px;border:1px solid #e0e0e0;border-radius:4px;\"\u003e\u003csummary style=\"cursor:pointer;font-weight:600;color:#1a1a1a;\"\u003eHow is it shipped and covered?\u003c\/summary\u003e\u003cp style=\"margin:8px 0 0;color:#444;\"\u003eCleaned, re-flashed and bench-tested on our own test line, with a 90-day warranty from delivery. Ask for photos of the actual unit before you commit.\u003c\/p\u003e\u003c\/details\u003e\n\u003cp\u003e\u003cem\u003eAvailable at \u003ca href=\"https:\/\/zhongxindata.hk\"\u003eZhongxin Data\u003c\/a\u003e — enterprise network hardware specialists. Worldwide shipping from Hong Kong, China.\u003c\/em\u003e\u003c\/p\u003e\n\u003cp style=\"font-size:13px;color:#666;\"\u003e\u003cem\u003eProduct image is a reference image for the form factor — revision, label and airflow sticker vary by batch. Ask us for photos of the actual unit before you commit.\u003c\/em\u003e\u003c\/p\u003e","brand":"NVIDIA Mellanox","offers":[{"title":"Default Title","offer_id":68061200154916,"sku":"MQM9790-NS2F","price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1017\/6223\/6708\/files\/5e17684c9e6a510c27dc900ac9548366.jpg?v=1793951603","url":"https:\/\/zhongxindata.hk\/products\/mellanox-qm9790-ns2f-400g-ndr-infiniband-switch-64-port-used","provider":"Zhongxin Data","version":"1.0","type":"link"}