[willglynn]

In 2024 I would suggest deploying 2x25G instead, via e.g. MCX4121. Pricing is similar (<$30 NICs), but:

* 2x25G throughput is higher than 40G,

* 25G latency is lower than 40G,

* you can use 25G ports as 10G ports, and

* you can use DACs to connect 4x25G <=> 100G

That last point is particularly relevant given the existence of switches like the Mikrotik CRS504, providing 4x100G ports on 25W.

[Palomides]

those are all reasonable points, if I were doing mine again I would spend a little more and go up to 100gbe

if you run all older mellanox gear the cx3 can do the kinda nonstandard 56gbe as well

[bombela]

What are you doing that you need 100gbe?

I am still on 1gbe... I guess I don't transfer anything bigger than a few GiB time to time.

[nickstinemates]

No individual connection other than like a cr tral storage server needs 100gbe, at least for me, but a 100gbe backplane is good for a lot of 1gbe poe devices as an example. With residential fiber/coax reaching 5gb, 1gb is not enough.