ClusterUpdated 2026-07-02 · 22 min read · by RTXsparks Lab
RTX Spark Cluster Setup: 2-Node to 4-Node Playbook
Complete guide to building a multi-node RTX Spark cluster with 10 GbE, ConnectX-7, and Ray Serve. Includes network, scheduler, and model-parallel configs.
Networking topology
For 2-node desk pairs, direct 10 GbE crossover works. For 3–4 nodes, use a 200GbE ConnectX-7 switch (Mellanox SN2201) to keep tensor-parallel latency under 40µs.
Model-parallel configuration
Set `--pipeline-parallel-size N` in vLLM and pin one worker per node. Verify NCCL sees all NICs with `NCCL_DEBUG=INFO`.
Frequently asked questions
Is 10 GbE enough?
Yes for pipeline parallelism up to 2 nodes. Tensor parallelism requires 100GbE+.