10Gtekfor Arista CAB-Q-Q-5M, 40Gb/s QSFP+ DAC Passive, 5m

Works as advertised (@ 40G) with a Mellanox ConnectX-3 and a Mellanox IS5022 unmanaged IB switch.

I bought a pair of these to use in my home lab. My company sent me a pair of EX3400 switches. Rather than spending tons of money on optics and cables, I decided to try these out after a recommendation on reddit. I'm a CCNP R/S, but my specialty is VoIP. So I'm not always up to date on datacenter fabric connections.These worked like a charm, and I was able to set up a virtual chassis with little effort. I was able to split port channels between the chassis. Everything works exactly as I would want. No errors from the switches. I'm currently running Junos 20.4R1.12.Since this is a lab, I cant comment on how they'd hold up in an actual datacenter application. But I would imagine they would work just fine.

I've used 10g tek stuff for a lot of installs. I recommend them to all my clients. These were used to stack a pair of ms-225s in a wiring closet and they came up perfectly. One month later I have no issues. OEMs are very proud of their cables and charge accordingly to put their name on them. 10g tek provides excellent cables for a great price.

Description states that it can run "up to 56Gb/s" when in actuality it can only run up to 40Gb/s (http://www.mellanox.com/page/cables; MC2206130-003 can only run at FDR10 which is 40GB/s). Other than that, it's a decent cable.--- Update ---I just wanted to give an update after running some more tests. These cables performed only slightly worse than our 56 Gbps AOC cables, simliar to  10Gtek 40G QSFP+ AOC, for IBM / Mellanox Active Optical Cable, 3-meter . We achieved 22.8 Gbps IPoIB with our AOC cables using iperf and got 22.3 Gbps with these copper cables. If you don't want to spend the extra money for optical cables and don't need to run long distances, this is a pretty good cable. 10Gtek 40G QSFP+ AOC, for IBM / Mellanox Active Optical Cable, 3-meter

Works with Mellanox ConnectX3 VPI and Celestica DX010 switch at 40g.