Too bad it's not a single SFP+ 10G cage, that would be actually useful then. :/
The number of people with faster than 1G internet is extremely small.
Business customers who have >1G commercial connections are not in the market for using ODROID boards for their routing needs.
2.5G is perfect for hobbyist use because it is significantly cheaper than anything 10G at the moment, while being faster than common 1G.
If you need 10G switching, get a 10G switch.
And then I might as well do that with an Intel NUC, or just go for a normal mini-ITX motherboard.
The PCIe slot on the H2 is PCIe 2.0 x4, which doesn't have enough bandwidth to saturate more than one 10G port.
This is why hobby hardware and the enthusiast market is so difficult: You can make a great product at a cheap price point and people will still complain that it doesn't satisfy their high-end niche edge case.
You can't do line rate on all ports either (limited by PCIe alone, let alone CPU for smaller packets), but you can certainly fill an individual port, which I suspect is the goal.
Are you sure about that? With 5GT/s (or 500MB/s) per lane, and with 4 lanes, that should be plenty, no? Intel adapters like the x520-DA2 are specced at 2x 10G, and use PCIe 2.0 x8.
FWIW, I was also able to iperf3 around 3.7Gbps on a X520-DA2 connected to an RPi4's single-lane PCIe 2.0.
Yah, I said forwarding-- so each packet goes over the PCIe link twice.
So, to use your test-- 3.7 x 4 / 2 = 7.4gbps. I said around 7. 7.4gbps would be a bit more than I'd expect, but I'd not be shocked.
Ethernet speeds are given in data bits per second, while USB 3.0, PCIe 1.0 and PCIe 2.0 add in their speed values the extra bits used for encoding.
On the other hand, 10 Gb/s USB and 8 Gb/s PCIe 3.0 have really those speeds. Complicated :-(
One PCIe 2.0 lane is more than enough for 2.5 Gb/s Ethernet, but not enough for 5 Gb/s Ethernet or 10 Gb/s Ethernet.
However, that is not due to being a cheap hobbyist board, but due to Intel, who have not provided their Atom line of CPUs with more lanes or with faster lanes.
Only the Elkhart Lake and Jasper Lake CPUs, which have been just launched by Intel as a replacement for the Gemini Lake Refresh CPUs used in ODROID H2, are the first Intel CPUs of the Atom series that have PCIe 3.0.
No, not really, it's the other way around. SFP+ based 10g networking equipment is much cheaper and and with much higher availability. And if needed, you can always adapt it to 1/2.5/5.10g networking using sfp+->rj45 transceivers. Only disadvantage was that you had to run fiber. Maybe it will change this year, bot for now 10g was a way to go
2.5G switches are expensive and rare. If you want to make use of multiple links to an L2 ToR, you have to set up LACP which is annoying. You could do ECMP for L3 LB instead, but that requires an even more expensive switch.
[1] - https://mikrotik.com/product/crs317_1g_16s_rm
EDIT: as for commitment, I'm literally looking to solve the problem of 'I want a low power k8s cluster, and I'm okay with a switch SPOF' for bgp.wtf's FMT location. If I could buy 5-6 of these, with 10G uplink, especially ready to rack, I'd probably order them today.
SFP+ is cheaper and better, but not exactly common in consumer networks where I imagine most low-cost ARM boards end up.
Right now the cheapest options are to get a 10Gb PCIe card from Newegg or similar, which'll run you about $200 where I am, and that's just a PCIe extension card.
If you want to go _very_ cheap and dirty you can get some FlexibleLOM/PCIe adapters [1] and some HP FlexibleLOM NICs [2]. This results in a 2x 10G NIC for around ~$15, including the adapter.
[1] - https://github.com/TobleMiner/HPE-FlexibleLOM-adapter
[2] - https://www.ebay.com/itm/HP-10GB-530FLR-649869-001-647579-00...
That said I think there's a market for boards between that $15 mark and the $200 I'd have to pay for something considerably higher-end.
[1] - https://www.cdw.com/product/hp-reman-enet-10gbe-530flr-sfp/3...
A 10 Gb/s Ethernet NIC from ASUS, with the Aquantia controller, is $93 at Amazon.
I use a few of those, bought in 2019, and they work fine.
https://www.amazon.com/ASUS-XG-C100C-Network-Adapter-Single/...
You can plug an M.2 to PCIe adapter and a used eBay 10GbE PCIe cards into the ODROID-H2+. A quick search showed several folks talking about this. eg: https://forum.odroid.com/viewtopic.php?t=39174 . It'd be nicer to have a straight M.2 to SFP+ but oh well.