Mellanox 655874-B21 QSFP+ to SFP+ Adapter Module 40G to 10G The Mellanox 655874-B21 (also known as HP 655874-B21) is a QSFP+ to SFP+ adapter module, designed to convert a 40G QSFP+ port into a 10G SFP+ port. It allows you to use standard 10G SFP+ transceivers (SR/LR/ER) in a 40G QSFP+ slot, providing flexible and cost-effective connectivity for data center switches, servers, and HPC equipment. This adapter is factory-calibrated for Mellanox and HP ProLiant/BladeSystem platforms.
Mellanox Part Number
655874-B21
Form Factor
QSFP+ to SFP+ Adapter (QSA)
Supported Speed
Host: 40Gbps; Client: 10Gbps
Standards
QSFP+ MSA, SFP+ MSA
Product Type
QSFP+ to SFP+ Adapter
Compatible Transceivers
10G SFP+ (SR, LR, ER, etc.)
Typical Applications - Data Center Migration: Connecting 10G SFP+ switches to new 40G QSFP+ switches using existing fiber cabling.
- HPC and Enterprise Servers: Deploying 10G SFP+ network adapters in servers with QSFP+ ports.
- Cost-Effective Connectivity: Using low-cost 10G SFP+ transceivers in high-density QSFP+ switch environments.
- Mellanox and HP Platforms: Certified for use in Mellanox InfiniBand/Ethernet switches and HP ProLiant/BladeSystem servers.
Product Highlights
1. 40G to 10G Breakout Function - This is a QSFP+ to SFP+ adapter module designed for Mellanox/HP switches and adapters.
- It converts a single 40G QSFP+ port into a single 10G SFP+ port, allowing you to use 10G SFP+ transceivers in 40G-capable equipment.
- This is a cost-effective way to add 10G connectivity to high-density 40G switches without replacing the hardware.
2. Standard Form Factor & Compatibility - The adapter fits into a standard QSFP+ cage and provides a standard SFP+ receptacle on the other end.
- It is validated for use with Mellanox switches (e.g., Spectrum) and HP/Enterprise servers and switches that support QSFP+ ports.
- The module supports hot-plugging, allowing for installation and removal without powering down the host device.
FAQ (Mellanox 655874-B21 QSA Adapter Module) Q1: What is the core function of this module? - This is a QSFP+ to SFP+ Adapter (QSA). It converts a 40G QSFP+ port on your device into a standard 10G SFP+ port, allowing you to use common 10G SFP+ transceivers (SR/LR/ER, etc.) directly in a 40G device.
Q2: Which devices and transceivers are compatible? - ✅ Device Compatibility: Certified for Mellanox/HP platforms, including:
- Mellanox Ethernet/InfiniBand switches and network adapters
- HP ProLiant/BladeSystem series servers
- Most standard QSFP+ interface devices (e.g., Cisco, Juniper)
- ✅ Transceiver Compatibility: Supports standard 10G SFP+ transceivers from major vendors, including:
- Multi-mode: 10GBASE-SR/SX
- Single-mode: 10GBASE-LR/ER/ZR, CWDM/DWDM
- ❌ Not Compatible: Does not support 40G/100G QSFP+ transceivers, and cannot perform reverse conversion (SFP+ to QSFP+).
Q3: What speed does it support? Will it affect performance? - No impact on performance: The adapter is a physical-layer converter only. It does not introduce additional latency or packet loss, and performs exactly the same as using a native 10G SFP+ port.
Q4: Does it require any additional configuration?
- It is plug-and-play in most scenarios with no extra setup needed:
- Once inserted into the QSFP+ port, the device will automatically recognize it as a 10G interface.
- Simply connect the corresponding 10G SFP+ transceiver, and the link will negotiate normally.
- On some specific vendor devices (e.g., certain Mellanox switches), you may need to enable qsa-mode or a similar compatibility setting. Please refer to your device's manual for details.
Q5: What are the advantages over using a native 40G transceiver?
- The main benefits are cost-effectiveness and flexibility:
- Cost Savings: Reuse existing 10G SFP+ transceivers, which are much more affordable than dedicated 40G QSFP+ modules.
- Flexibility: Works with different 10G transceivers for various distances and types, adapting to multiple scenarios.
- Smooth Migration: During data center upgrades from 10G to 40G, you can keep your existing 10G fiber cabling and still use new 40G equipment.