Cisco QSFP-H40G-CU1M 1m 40GbE QSFP+ Direct Attach Cable - Passive Twinax Copper DAC for Switches
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Product Features
Technical Overview
This 40GbE direct attach cable utilizes a twinaxial copper construction with 30 AWG conductors and 100-ohm impedance, optimized for signal integrity over its 1-meter length. The passive design requires no external power, drawing minimal energy from the host switch while delivering full 40 Gbps throughput.
The QSFP+ connectors comply with MSA (Multi-Source Agreement) standards, ensuring mechanical and electrical interoperability with a wide range of networking equipment. The PVC jacket provides durable protection in data center environments while maintaining flexibility for cable management.
This section brings together practical product details such as Cable Type, Cable Length, Connector Type on First End, Color Family, so buyers can judge configuration, deployment fit, and day-to-day suitability with less guesswork.
Key Product Advantages
This direct attach cable offers several advantages over alternative connectivity solutions for 40GbE deployments. The copper twinax construction provides significant cost savings compared to optical transceivers and fiber cabling, while delivering equivalent performance for short-distance connections.
Proven Cisco Compatibility
Extensively tested with Cisco Catalyst 9000 series switches, this cable ensures reliable operation without compromising OEM support agreements or warranty coverage.
- 100% compatible with Cisco QSFP-H40G-CU1M
- Works with C9300/C9200/C9400/C9500/C9600
- Won't void Cisco support agreements
Broad Platform Support
Beyond Cisco ecosystems, this cable functions with any MSA-compliant switch that accepts uncoded QSFP+ modules, including platforms from Ubiquiti, D-Link, Netgear, Supermicro, and TP-Link.
- MSA compliance ensures interoperability
- Low-power design compatible with various switches
- Hot-swappable for easy installation
Lifetime Warranty Protection
Backed by StarTech.com's lifetime warranty covering the cable itself, providing long-term investment protection and peace of mind for network infrastructure deployments.
- Coverage for the life of the cable
- Technical support available
- Quality assurance from established manufacturer
Deployment / Use Cases
This 40GbE direct attach cable is ideal for connecting switches within the same rack or adjacent cabinets in data center environments. The 1-meter length is optimized for top-of-rack switching configurations where minimal cable run is required between devices.
Common deployment scenarios include spine-leaf architectures, server-to-switch connections in high-performance computing clusters, and aggregation layer connectivity in enterprise networks. The cable supports both data center bridging (DCB) and Ethernet protocols, making it suitable for converged network environments carrying storage, data, and management traffic.
Data Center Interconnects
Connect top-of-rack switches to aggregation switches within the same rack, minimizing latency and cable clutter while maximizing 40GbE port utilization.
- Rack-mounted switch connections
- Server-to-switch links
- Intra-rack connectivity
Network Upgrades
Cost-effectively upgrade existing 10GbE links to 40GbE without replacing entire fiber infrastructure, leveraging existing QSFP+ switch ports.
- 10GbE to 40GbE migration
- Port density optimization
- Backward compatibility planning
Physical Profile
The cable features a black PVC jacket that blends with standard data center color schemes while providing abrasion resistance and flame-retardant properties. With a weight of just 2.54 ounces (72 grams), the cable adds minimal load to cable management systems while maintaining the flexibility needed for tight bend radius installations common in high-density network environments.
- Weight
- 2.54 oz (72 g)
- Length
- 3.3 ft (1 m)
Highlights
- 100% compatible with Cisco QSFP-H40G-CU1M specification
- 1-meter (3.3-foot) 40GbE passive twinax copper cable
- QSFP+ male connectors on both ends for direct switch-to-switch connections
- Hot-swappable design allows installation without network downtime
- MSA-compliant for broad compatibility beyond Cisco ecosystems
- 30 AWG copper conductors with 100-ohm impedance
- Black PVC jacket for durability and standard data center aesthetics
- Lifetime warranty from StarTech.com
- RoHS and WEEE compliant for environmental responsibility
- Tested with Cisco Catalyst 9000 series switches
Specifications
| Specifications | |
|---|---|
| Manufacturer | StarTech.com |
| Manufacturer Part Number | QSFPH40GCU1M |
| Brand Name | StarTech.com |
| Product Name | Cisco QSFP-H40G-CU1M Compatible - QSFP+ Direct Attach Cable - 1 m (3.3 ft.) |
| Packaged Quantity | 1 Each |
| Product Type | Network Cable |
| Technical Information | |
| Cable Type | Twinaxial |
| Cable Length | 3.3 ft (1 m) |
| Connector Type on First End | QSFP+ Network - Male |
| Connector Gender on First End | Male |
| Connector on First End Details | 1 x QSFP+ Network - Male |
| Connector Type on Second End | QSFP+ Network - Male |
| Connector Gender on Second End | Male |
| Connector on Second End Details | 1 x QSFP+ Network - Male |
| Device Supported | Network Device,Server,Switch,Transceiver,Router |
| American Wire Gauge | 30 AWG |
| Data Transfer Rate | 40 Gbit/s |
| Features | Passive,Hot-swappable |
| Physical Characteristics | |
| Color Family | Black |
| Product Color | Black |
| Product Material | Copper |
| Jacket Material | Polyvinyl Chloride (PVC) |
| Weight (Approximate) | 2.54 oz (72 g) |
| Miscellaneous | |
| Compatibility | Cisco Switches: C9300 C9200 C9400 C9500 C9600 |
| Environmentally Friendly | Yes |
| Environmental Compliance | Restriction of Hazardous Substances (RoHS),Waste Electrical and Electronic Equipment Directive (WEEE) |
| Country of Origin | Taiwan |
| Warranty | |
| Limited Warranty | Lifetime |
User Manual
FAQ
What switches is this QSFP+ direct attach cable compatible with?
This cable is specifically designed for compatibility with Cisco Catalyst 9000 series switches including the C9300, C9200, C9400, C9500, and C9600 models. It also works with any MSA-compliant networking equipment that accepts uncoded QSFP+ modules, including switches from Ubiquiti, D-Link, Netgear, Supermicro, and TP-Link. The cable maintains 100% compatibility with the original Cisco QSFP-H40G-CU1M specification.
What is the difference between passive and active direct attach cables?
This is a passive direct attach cable, meaning it contains no active electronics or signal amplification components. Passive cables are simpler, more reliable, and consume less power than active cables, making them ideal for short-distance connections up to 3-5 meters. They're also typically more cost-effective while delivering the same 40 Gbps performance for rack-level deployments where signal integrity can be maintained without amplification.
Can I hot-swap this cable without powering down my switch?
Yes, this cable features hot-swappable QSFP+ connectors that allow installation or replacement without powering down the connected networking equipment. This capability minimizes network downtime during maintenance, upgrades, or reconfigurations. The cable complies with the hot-plug specifications defined in the QSFP+ MSA, ensuring safe insertion and removal while the switch remains operational.
What is the maximum distance for this 40GbE direct attach cable?
This 1-meter (3.3-foot) cable is optimized for short-reach connections typically found within the same rack or between adjacent cabinets in data center environments. Passive twinax copper cables generally support distances up to 3-5 meters for 40GbE applications, with this specific length being ideal for top-of-rack switching configurations where minimal cable run is required between directly connected devices.
Does using this third-party cable void my Cisco switch warranty?
No, this StarTech.com direct attach cable is designed not to void your Cisco OEM support agreements. The cable is 100% compatible with Cisco's QSFP-H40G-CU1M specification and has been tested to work seamlessly with Cisco switching platforms. StarTech.com stands behind their compatibility claims and provides a lifetime warranty on the cable itself, separate from your equipment manufacturer's coverage.
What environmental standards does this cable comply with?
This cable meets Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment Directive (WEEE) compliance standards. These regulations ensure the product contains minimal levels of hazardous materials and can be properly recycled at end-of-life. The environmentally friendly design, combined with the durable PVC jacket and copper construction, supports sustainable IT infrastructure practices.
| Qty | Price | Available |
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