Mellanox SN3800-CS2RO 100GbE 64-Port QSFP28 Switch 2U Used
Quick answer: NVIDIA Spectrum-2 SN3800 MSN3800-CS2RO used, bench-tested. NVIDIA Spectrum-2 SN3800 with 64 QSFP28 ports at 100GbE, 6.4 Tb/s switching capacity (64 × 100GbE, non-blocking), 2U, C2P airflow, shipping as an ONIE build so you choose the network OS.
In stock: MSN3800-CS2RO is in stock — availability is confirmed per part number, so send the exact model you need and we check the shelf before quoting.
Need a quote? Message WhatsApp +86 13068616914 with the part number (for example MSN3800-CS2RO) 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.
NVIDIA Spectrum-2 SN3800
The NVIDIA Spectrum-2 SN3800 (CS2RO) doubles port count instead of port speed: 64 QSFP28 ports at 100GbE, 6.4 Tb/s switching capacity (64 × 100GbE, non-blocking), line-rate on all 64 ports and a 42 MB buffer in 2U. That makes it a spine for racks of 25G and 100G servers without breaking the rack into more 1U leaves. This build is ONIE-only, so it arrives without a pre-installed network OS.
Condition: Used — cleaned, re-flashed and bench-tested on our own test line before it is listed. 90-day warranty from delivery.
| Specification | Details |
|---|---|
| Part number | MSN3800-CS2RO |
| Family | NVIDIA Spectrum-2 SN3800 |
| Switch silicon | NVIDIA Spectrum-2 |
| Ports | 64 × 100GbE QSFP28 |
| Port speed | 100GbE per port (50/40/25GbE with breakouts; up to 200GbE on QSFP56 builds) |
| Connectors | QSFP28 (64 ports) |
| Switching capacity | 6.4 Tb/s switching capacity (64 × 100GbE, non-blocking) |
| Packet buffer | 42 MB shared packet buffer |
| Airflow | C2P — connector-to-power (back-to-front) |
| Form factor | 2U rackmount |
| Dimensions | 88 × 428 × 559 mm |
| Power | 2 × hot-swap AC PSU (1+1), 3 × hot-swap fans |
| Management | x86 quad-core control plane, 8 GB RAM |
| Software | ONIE — install Onyx, Cumulus Linux or SONiC |
Key features
- 64 × 100GbE QSFP28 ports in 2U
- 6.4 Tb/s switching capacity (64 × 100GbE, non-blocking), line-rate on all 64 ports
- 42 MB shared buffer for lossless RoCEv2
- Breakout to 4 × 25GbE per port (up to 256 × 25GbE)
- ONIE build — install Onyx, Cumulus Linux or SONiC
- C2P airflow, 3 hot-swap fans, dual PSU
Typical deployments
100G spine and super-spine layers, dense 25G server aggregation, storage fabrics and leaf-spine fabrics in reverse-cooled racks.
What is included
- Switch chassis with both power supplies
- Fan units (C2P)
- Rail kit
- Condition report and bench-test notes
Not included
- Network OS image and licence (ONIE build)
- QSFP28 optics and cables
MSN3800-CS2RO in the lineup
Pick the SN3800 when port count is the constraint: 64 × 100G in 2U versus 32 × 100G in 1U on the SN3700C. If you would rather pay for 200G ports and split them, the SN3700-VS2F/VS2R or SN4600 is the better fit.
How it compares with models we also stock
| Model | Fabric | Ports | Best for |
|---|---|---|---|
| MSN3800-CS2RO | Ethernet 100G | 64 QSFP28 | Dense 100G spine, ONIE, C2P |
| MSN3800-CS2F | Ethernet 100G | 64 QSFP28 | Same chassis with Onyx, P2C |
| MSN3700-CS2F | Ethernet 100G | 32 QSFP28 | Half the ports in 1U |
| MSN4600-VS2RC | Ethernet 200G | 64 QSFP56 | Same 2U body at 200G |
Why buy this switch from Zhongxin Data
- Bench-tested on our own in-house test line — ports, fans and power supplies are checked before the unit leaves.
- We quote only what we can physically confirm: the exact part number, airflow direction and condition notes come from the unit in front of us.
- Used enterprise switches at secondary-market pricing, with a 90-day warranty from delivery.
- Worldwide shipping from Hong Kong, China; consolidation with servers, NICs and optics from the same rack is routine.
Request a quote
Send the part number MSN3800-CS2RO, the quantity you need and your destination to WhatsApp +86 13068616914 (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.
Frequently asked questions
Does this switch come with a network operating system?
No. CS2RO is the ONIE build: the unit boots into ONIE and you install Onyx, Cumulus Linux or SONiC. If you want a pre-installed image, take the CS2F build instead.
How many ports and what speed?
64 QSFP28 ports at 100GbE, each able to break out to 4 × 25GbE.
What does CS2RO mean?
C for 100GbE, S2 for the standard-depth chassis, R for connector-to-power airflow, O for ONIE.
Is it 1U or 2U?
2U. The SN3800 chassis is 88 mm high and weighs around 16.7 kg, so plan the rail kit and rack depth accordingly.
Can it do 200G or 400G?
Not on this build. The 100G ceiling comes from the QSFP28 port class; 200G and above need QSFP56 or QSFP-DD platforms such as the SN4600 or SN5600.
Is it an InfiniBand switch?
No — Ethernet with RoCEv2. InfiniBand is the Quantum QM series.
What warranty is included?
90-day warranty from delivery, after bench testing on our own line.
Available at Zhongxin Data — enterprise network hardware specialists. Worldwide shipping from Hong Kong, China.
Product 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.