> Intel's Omni-Path was very similar but a little different from Infiniband.
While Intel may have had the 'IB-adjacent' Omni-Path, they also had plain-old IB as well. I ran these/similar switches for an Isilon back-end network (starting when Isilon was still an independent company, pre-EMC buyout, pre-Dell buyout, in the OneFS 6.x days):
* https://www.dell.com/support/kbdoc/en-us/000019215/install-a...
Intel bought Qlogic's IB division when they sold it off, in 2012; I believe at one point the former QLogic parts were branded Omni-Path before it diverged. (You can still see the DNA of that in how the Omni-Path driver stack is a relative of the Qlogic drivers, last I knew.)
Before that, Mellanox ate Voltaire, who was the other large vendor in the IB space.
So at this point, I believe NVIDIA's Mellanox devices are the only people selling IB chips these days, and glancing at the TOP500 from June, seems like a good half (45.8%) of the supercomputers listed there are using either Ethernet-based or otherwise non-IB stacks.
> […] seems like a good half (45.8%) of the supercomputers listed there are using either Ethernet-based or otherwise non-IB stacks.
I've done HPC for the last little while, but mostly Eth-based. Lately I have done a smattering more of IB, and (AFIACT) the main advantage IB gets you is lower latency (both 'innately' at the network layer, and with more 'out-of-box' RDMA).