Connectx 5 Ex (MCX516A-BDAT) with QSFP28 (40 Gbps) connection to SFP+ 10 Gbps

[atorre]

I have a Connectx 5 Ex (MCX516A-BDAT) with a QSFP28 port that I want to connect to a 10 GbE switch with SFP+ ports. I have seen two options to do this:

• A breakout cable. In https://community.mellanox.com/s/article/mellanox-breakout-cables-40g--gt--4x10g-and-100g--gt--4x25g it is said that breakout cables only work on the switch side, not on the NIC side. Is this true?
• An adapter such as https://store.mellanox.com/products/nvidia-mam1q00a-qsa-sp-single-pack-mam1q00a-qsa-ethernet-cable-adapter-40gb-s-to-10gb-s-qsfp-to-sfp.html

Are both options valid?. Which do you recommend?

[MvB]

Hello Alberto,

Thank you for posting your inquiry on the NVIDIA Networking Community.

Based on the information provided, yes unfortunately the break-out option is only available on the switch side. The adapter is still able to connect to the end of the break-out cable (1 of the 25GbE ends)

The module you are referring to (MAM1Q00A-QSA) is validated and supported for converting from QSFP to SFP+. The following link from the latest f/w RN of the adapter will give you a few more options → https://docs.mellanox.com/display/ConnectX5Firmwarev16282006/Firmware+Compatible+Products#FirmwareCompatibleProducts-ValidatedandSupported10GbECables

Such as using a hybrid cable like the MC2309124-00x.

Thank you and regards,

~NVIDIA Networking Technical Support