Introduction
As AI workloads, NVMe-oF storage fabrics, and high-density virtualization push network demands beyond 10GbE, 100GbE datacenter switches have become the new baseline for modern infrastructure. Mellanox Spectrum switches are among the most widely deployed 100GbE platforms in the world — and for good reason.
This guide introduces the Mellanox Spectrum switch family, explains key specifications, and helps you choose the right model for your environment.
Why 100GbE?
10GbE was the datacenter standard for over a decade, but modern workloads have outgrown it:
- NVMe SSDs can saturate a 10GbE link in milliseconds
- GPU-to-GPU communication in AI clusters requires ultra-low latency and high bandwidth
- Storage replication and backup windows shrink dramatically at 100GbE
- A single 100GbE uplink replaces four 25GbE links, simplifying cabling
Mellanox Spectrum Switch Family Overview
SN2700 — 32-Port 100GbE
The SN2700 is the most widely deployed Mellanox Spectrum switch. It offers 32 ports of 100GbE QSFP28 in a 1U form factor, with a total switching capacity of 6.4 Tbps.
- Ports: 32x 100GbE QSFP28
- Throughput: 6.4 Tbps / 4.76 Bpps
- Latency: Cut-through under 300ns
- Best for: Top-of-rack (ToR) switching, spine-leaf fabrics, NVMe-oF
SN3700 — 36-Port 100GbE High Density
The SN3700 uses the Spectrum-2 ASIC and delivers 36 ports of 100GbE with enhanced RoCE v2 and in-network computing capabilities.
- Ports: 36x 100GbE QSFP28
- Throughput: 7.2 Tbps
- Features: SHARP in-network aggregation, enhanced RoCE v2
- Best for: AI/ML clusters, HPC spine switches
SN3800 — 64-Port 100GbE
The SN3800 is a 2U high-density switch with 64 ports of 100GbE, ideal for large spine layers or aggregation switching.
- Ports: 64x 100GbE QSFP28
- Throughput: 12.8 Tbps
- Best for: Spine aggregation, large-scale storage clusters
Key Features of Mellanox Spectrum Switches
- Onyx OS: Mellanox’s native NOS with full CLI, REST API, and Ansible support
- Open Ethernet: Supports Cumulus Linux, SONiC, and other open NOS options
- RoCE v2: Hardware-accelerated RDMA over Ethernet for NVMe-oF and AI workloads
- Cut-through switching: Sub-300ns latency for latency-sensitive applications
- ECMP: Equal-cost multipath routing for spine-leaf load balancing
Spine-Leaf Architecture with Mellanox Spectrum
The most common deployment pattern for Mellanox Spectrum switches is a spine-leaf fabric:
- Leaf switches (SN2700): Connect servers via 25GbE or 100GbE uplinks
- Spine switches (SN3700/SN3800): Interconnect all leaf switches with 100GbE uplinks
- This architecture provides predictable latency, easy scaling, and full bisectional bandwidth
Buy Refurbished Mellanox Spectrum Switches
Zhongxin Data stocks refurbished Mellanox SN2700, SN3700, SN3800, and SN4600 switches. All units are fully tested, firmware-verified, and shipped with warranty from Hong Kong.
Contact us for bulk pricing or configuration assistance.