Are QSFP28 and QSFP56 compatible with older QSFP+ slots?
Are QSFP28 and QSFP56 compatible with older QSFP+ slots?
I have a question about whether my Mellanox NIC works with my Arista switch. My company has an old Arista switch (7050SX-72Q) that they want to keep for a few more years. It has six 40 Gbps QSFP+ ports. I am building out a system for my company, and one rule is 40 Gbps or higher connectivity. I wanted to buy this Mellanox NIC (MCX653106A-HDAT-SP) to connect it to the switch right now so I can upgrade the switch later. When I asked if they were compatible before, someone told me that QSFP56 (what the Mellanox uses) does not work with QSFP+ ports on the Arista switch at least until now. But after doing some more research, I found out maybe it's not true. So here is my question to you all: can I plug this Mellanox NIC into my company's Arista switch (for now since connectivity will be capped at 40 Gbps), and then upgrade the switch later? Or do I have to buy an older NIC that has QSFP+ ports to connect directly to the Arista switch? If it is possible for QSFP56 ports (from Mellanox) to work with QSFP+ ports (on the Arista), can I assume I'd need some sort of breakout optical cable to go from QSFP56 to QSFP+? If so, could someone recommend such a cable? Thank you, Nelson
I told you be careful and suggested you call the maker. The data sheet says it works with many speeds. What I meant was maybe one type of light works for all speeds, but other lights are needed because they have special chips inside them. I don't hold any equipment to look at that card. A Wikipedia page said this new type isn't backward compatible, which is why you need to call Mellanox directly. Being in the defense industry means companies like them will answer emails. If you can use your company email instead of a personal one, they are more likely to reply quickly.
Hello Kane Wolf, I reached out to Mellanox a few days ago and received these words: "Hi Nelson, we confirmed that our dual-port version of this card worked fine. Please let me know if you have any other questions." ... but the answer felt pretty vague (since they didn't say what exactly they tested on - like my Arista switch), and honestly, I thought they just misunderstood my question. That's why I turned to the online community for help. I sent them another email asking if their QSFP56 ports work with QSFP+ ports (for my switch). Hopefully they reply soon; if not, someone in this group could probably give some clarity (since I'm seeing conflicting info online on it). Thanks, Nelson