Mellanox Connectx-4 40gbe QSFP possible?

[ycp]

Hello,

I have a Mellanox Connectx-3 40gbe QSFP ethernet card.
I was wondering if the same port is available in any of the Connectx-4 models?

 

[i386]

I'm don't understand what you're asking
The cx-4 use qsfp28 or sfp28 connectors. Both are backwards compatible to qsfp14/qsfp+ and sfp14/sfp+ aka 40GBE and 10GBE

 

[NablaSquaredG]

ConnectX-4 supports 1G, 10G, 40G, 56G and 100G (depending on the model / firmware, 56G / 100G may not be available)

 

[ycp]

Sorry for the confusion.
Basically i have a Dell Force10 S4810 and this switch only has QSFP ports not any sfp28.
Which connectx-4 model would be compatible with the s4810 for 40gbe ethernet?
I didn't know that SFP28 ports are backwards compatible with QSFP ports.
If that is the case then is it safe to assume that any Connectx-4 model will work with the S4810 switch?

 

[NablaSquaredG]

Get yourself a CX416A, CX415A, CX456A or CX455A - they can all be crossflashed to the -ECAT variant and will then do 40G, 56G and 100G

 

[i386]

I didn't know that SFP28 ports are backwards compatible with QSFP ports.

sfp28 is backwards compatible to the other sfp form factors. If you want to connect it to any qsfp connect you will need an adapter like MAM1Q00A-QSA28 NVIDIA DynamiX QSA™ QSA28, QSFP28 to SFP28 Adapter Product Specifications - MAM1Q00A-QSA28 NVIDIA DynamiX QSA™ QSA28, QSFP28 to SFP28 Adapter Product Specifications - NVIDIA Networking Docs

 

[ycp]

Would this below model work without any adapters?
MCX4131A-BCAT Mellanox ConnectX-4 Lx 1x40GbE QSFP+ Adapter

 

[NablaSquaredG]

Yes (assuming you want to connect it to one of the QSFP ports of the SF4810), the card supports 1x 40G in a QSFP port.

Just be aware that CX455A (which has PCIe3.0 x16 and supports up to 100GBit, the CX4131A only has x8 and supports 40GBit) are priced around $100 on ebay...

 

[ycp]

@NablaSquaredG Thanks for the tips
One more question. If i get the CX455A will i need some sort of adapter to connect to my SF4810 switch?
Or can i use existing QSFP DAC cables that i use with the ConnectX-3?

 

[NablaSquaredG]

You can use the same cable