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by fulafel 987 days ago
10Gb ethernet is 20+ year old tech and and used these days in applications that don't have high bandwidth demands. 100 Gb (and 40 Gb for mid range) NICs came around 2014. People were building affordable home 40 Gb setups in 2019 or so[1]. But I can believe you that the low-end makes up a lot of the volume in the server market.

[1] https://forums.servethehome.com/index.php?threads/cheap-40gb...
1 comments
packetslave 987 days ago
In my experience, 40gb and 100gb are still mostly used for interconnects (switch/switch links, peering connections, etc.). Mostly due to the cost of NICs and optics. 25gb or Nx10gb seems to be the sweet spot for server/ToR uplinks, both for cost, but also because it's non-trivial to push even a 10gb NIC to line rate (which is ultimately what this entire thread is about).

There's some interesting reading in the Maglev paper from Google about the work they did to push 10gb line rate on commodity Linux hardware.

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fulafel 987 days ago
I guess it'll also depend a lot on what size of server you have. You'd pick a different NIC for a 384-vCPU EPYC box running a zillion VMs in a on-prem server room than a small business $500 1u colo rack web server.

The 2016 Maglev paper was an interesting read, but note that the 10G line rate was with tiny packets and without stuff like TCP send offload (because it's a software router that handles each packet on CPU). Generally if you browe around there isn't issue with saturating a 100G nic when using multiple concurrent TCP connections.

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