[jacquesm]

Ah! Ok, thank you now I get it. That's a very nice rig you have there. So at a guess you didn't care as much about the peak computing capacity as long as whatever you are doing all fits in GPU memory and this is your way of collecting that much memory in a single machine so you still have reasonable interconnect speeds between GPUs?

[ftufek]

Yeah, it's really just trying to get as much compute as possible as cheaply as possible interconnected in a reasonably fast way with low latency. Slow networking would be a bottleneck and expensive high end networking would defeat the purpose of staying cheap.

[buildbot]

You’d be surprised at how cheap high end networking that outperforms PCIE4 x4 is - 100Gb omni-path nics are running for 20$ on ebay! And those will saturate PCIE3 x16.

Though of course with multiple boards/ram/cpu it gets complicated again.

[magicalhippo]

Which cards? Been looking at nics but couldn't find cheap ones past 25-40Gb

[justinclift]

Omni-path is/was the Intel fork of Infiniband, which from rough memory they bought from QLogic some years ago.

* Switch: https://www.ebay.com/itm/273064154224

* Adapters: https://www.ebay.com/itm/296188773061 / https://www.ebay.com/itm/166199451199

* Cables: No idea, sorry. ;)

* Description: https://www.youtube.com/watch?v=dOIXtsjJMYE

Note that I don't know those Ebay sellers at all, they're just some of the cheaper results showing up from searching. There seem to be plenty of other results too. :)

---

Possibly useful, though it's Proxmox focused:

https://forum.level1techs.com/t/proxmox-with-intel-omni-path...

[jacquesm]

Very smart approach. I may copy your setup for some project that I've been working on for years but that stalled waiting for more memory in GPUs.