DAC Cables

How to Choose a DAC Cable

Four checks cover almost every DAC order. Get these right and the cable links the first time.

1. Match the port, not just the speed

The port on each end sets the speed. SFP+ carries 10G, SFP28 carries 25G, QSFP+ carries 40G, QSFP28 carries 100G and QSFP56 carries 200G. At 400G and above there are three form factors: QSFP-DD, QSFP112 and OSFP. They are not interchangeable even at the same speed, so check the cage on your NIC or switch before ordering.

2. Get the coding right

Switches read the EEPROM in each cable end to confirm vendor and part number. Cisco, Arista and Juniper can log warnings or disable a port when the coding doesn't match. Every cable here is coded for the platform named in its title and tested before it ships. If the two ends plug into different brands, ask us before ordering.

3. Keep it short

Passive DAC is for in-rack and next-rack runs. At 25G and 100G it reaches about 3m, and at 200G and above the maximum length is shorter. For longer runs, use AOC cables or transceivers with fiber.

4. Breakouts need port configuration

A 100G-to-4×25G or 400G-to-2×200G breakout links only after the switch port is split in its configuration. All breakouts are also listed under Breakout Cables.

DAC Part-Number Lookup

Find your OEM part number, then click through to the matching cable.

Running NVIDIA/Mellanox gear across generations? The NVIDIA/Mellanox Interconnect Compatibility Guide maps which cables fit which NICs and switches. Don't see your part number? Request a quote, since we can often source parts that aren't listed.