We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in

Black Box Corporation

Black Box QSFP-H40G-CU1M-BB 40 Gbps DAC network ethernet cable 3.28 ft

SKU CH-C32F-7HGMY

Passive QSFP+ direct-attach cable links switches, routers and servers at 40 Gbps over 3.28 ft

  • 40 Gbps data rate supports high-bandwidth networking
  • 28 ft passive DAC reduces power consumption in-rack
  • 100 % Cisco QSFP-H40G-CUxM compatible for drop-in deployment
  • MSA and SFF-8436 compliant for multi-vendor interoperability
  • QSFP+ male connectors on both ends link switches, routers and servers

40 Gbps QSFP+ Direct Attach Cable

This Black Box QSFP+ DAC connects switches, routers and servers at up to 40 Gbps over a 3.28 ft passive copper assembly. It is programmed, tested and serialized for full MSA and SFF-8436 compliance and 100 % Cisco QSFP-H40G-CUxM= compatibility. The cable suits data-centre, storage and high-performance computing links where low latency and low power matter.

In-rack high-density 40 Gbps links

Network engineers building short-reach, high-bandwidth top-of-rack or intra-rack fabrics will appreciate the passive design and multi-vendor interoperability. Buyers who need longer reach, active signal conditioning or fibre-based media should look at alternative cable types. The fixed 3.28 ft length also rules out deployments that require greater rack-to-rack distance.

40 Gbps throughput headroom

The passive copper construction comfortably handles full 40 Gbps Ethernet and Fibre Channel traffic within the specified 3.28 ft span. Beyond that distance signal integrity degrades, so the cable runs out of headroom for extended runs or higher-speed standards such as 100 Gbps.

Highlights

  • 40 Gbps data rate supports high-bandwidth networking
  • 28 ft passive DAC reduces power consumption in-rack
  • 100 % Cisco QSFP-H40G-CUxM compatible for drop-in deployment
  • MSA and SFF-8436 compliant for multi-vendor interoperability
  • QSFP+ male connectors on both ends link switches, routers and servers

Specifications

BrandBlack Box

Questions about this item

Which ports must my switch or server already have to plug this 40 Gbps DAC in?

Both ends use a QSFP+ male connector, so each device needs a matching QSFP+ port.

Will this passive 3.28 ft cable work with my older 10 Gbps SFP+ gear if I keep it?

No, the QSFP+ interface is physically and electrically different from SFP+ and cannot mate with it.

How can I confirm the link is running at the rated 40 Gbit/s after I connect it?

Check the switch or server interface status; it should report a 40 Gbps link with no errors.

New to this? Which coin should you pay with — what to check, what it costs to pay, and what is never asked for.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.