Offload support that works well under OpenWrt / Linux networking stack
I’ve looked at boards like the Banana Pi R64, but as far as I understand, the Ethernet PHYs there don’t support features like PTP or tc offloading or similar things. Does anyone know of suitable alternatives that come close to the APU2 in terms of NIC capabilities and expansion options?
Without the WLAN requirement, there'd be plenty potential options with gemini-lake j4xxx or ryzen embedded r1xxx/ v1xxx on the used markets, in the thin-client space. Usually only one (and often realtek) 1 GBe port, but a second can often be retrofitted easily, by sacrificing the (single) E-key M.2 'wlan' slot. Pretty good performance, low power requirements (starting around ~3 watts idle for the Atom based ones, starting around 8 watts for the ryzen embedded ones).
Yes, this is quite far from your requirements - but 2* ethernet and >=2 slots for WLAN is very hard to find below µATX.
Technically speaking the s740/ s7010 (with the stripped down mainboard) have two PCIe slots (1* B key 2280, single PCIe v2 lane && SATA3, 1* E key 2230, single PCIe v2 lane), but you need one of them for the main storage… (are there weird adapters splitting a single B+M key M.2 into independent PCIe and SATA carrying slots?).
Many of the alderlake-n (n100 and friends) mini-PCs (the four GBe port firewall PCs usually won't) from Jack Ma's market place do have two 1 GBe ports, one M.2 M-key flot for an SSD, one M.2 E-key 2230 slot for a WLAN card; you will find options with either realtek or Intel ethernet among them.
GX-412TC would be something I'd rather skip, than buy these days - no real improvement compared to the APU2 there.
And all of the examples above (including the j4xxx/ r1xxx/ v1xxx) will have trouble keeping an AP-capable WLAN card cool and to provide enough power to them. The combination (slots, cooling, power delivery) just isn't very realistic for <<µATX (or proprietary SFF) systems.
A skylake/ kabylake i3/ i5 SFF systems from one of the big four (Dell, Fujitsu, HP, Lenovo) can get away with just under 20 watts idle, if you throw out the 3.5" HDD in favour of an NVMe SSD (depending on the model, you may or may not need a desktop PCIe <--> M.2 adapter), one onboard ethernet card, 3-4 half-height PCIe slots available for ethernet/ wlan…
Not great, but close. It's the smallest (readily/ cheaply available on the second hand markets) option I can think of, which can actually drive SSD, >=2* ethernet and 2* WLAN. Will need ~10-15 bucks worth of desktop-PCIe --> M.2 adapters and idle power consumption will not be perfect, but maybe good enough.
I use this board. I used to have two mini pci-e WLAN cards (Compex ones) in it on a pce-e carrier board that with two slots, although now use separate APs
There are many different variants. Most have 4 ethernet ports and a single pcie x4 slot. You can even get 16 core variants and some have 10G SFP+ ports on them. The nics are Intel and use ixgbe, so nicely tunable and have tc offloading (I even made a port of the Intel QAT drivers to openwrt 19.07).
I upgraded my APU3D4 to a small Xeon server (Fujitsu Primergy TX1320). It can run on less than 10W with the two on-board i210, and has PCIe slots for more. I’m satisfied with it.
if we're going to name drop devices, there's also the 100€ HP T740.
it got a M.2 slot for a wifi card.
add a single, dual or quad port low profile NIC.
I have switched from APU2 to DFI ADN-553 and ASL-553 boards for use in industrial systems, with a custom aluminium extrusion enclosure and DIN mount. They have 3x i225 ethernet, 3x m.2 slots (2280 m-key for disk, 2230 e-key for WiFi and b-key for modem) and require a DDR5 RAM module. Similar boards that would fit the same enclosure are available from "Piesia" (through Jack Ma's online stores) and "Aaeon".
The main M.2 slot for WiFi is only 2230 size and limits you to client cards unless you use a riser or extender module. On the M-key slot you could use an adapter card. Otherwise these boards are excellent for routing and running docker containers.
If you or someone else actively develops for OpenWRT and could help with improving board support in OpenWRT I can offer to send a development kit. I build custom images for these, but it would be nice if for instance the ethernet ports are in the correct order and assigned out-of-the-box.
Also if you want to use any 3.5" SBC and just need a custom 168x120x45mm DIN-rail enclosure, contact me for details, it would be nice to get this into the public.
Sorry for being a little stingy on the info, but I guess I can post it here without it becoming a sales pitch.
This enclosure consists of a u-shaped extrusion with a slide-in side panel, rear panel with DIN-clip and a front panel. A complete set costs approximately 45 euro, but requires you to drill and tap the holes for the mounting studs. I have the tools to do this as well, including custom laser engraving.
I own the extrusion mold and the design is currently used in small quantities for proprietary products, but it's great for generic SBC use. I would like to hear if there is interest in this.
I understand now that you meant the mainboards...
The DFI boards I mentioned are only for sale B2B and prices are around 300 euro (excl. RAM and SSD). For the quantities I need I have supply set up and have some to spare for developers. Similar boards from Piesia (AD743AW) can be bought directly from the manufacturer and I would also be interested to try some of these (bulk buy and share cost?): https://piesia.en.alibaba.com/productgrouplist-944606830/3_5_inch_motherboard.html
The AD30NA4L model even has 4x ethernet and would also fit in the enclosure, but has connectors on both sides, so won't work with DIN mounting.
In general the Intel Atom boards are currently in limited supply, since Intel significantly cut production because of the "AI bubble". But any 3.5" SBC would fit in that enclosure and newer Core Ultra models are coming out now.
But I will keep my eyes open. Sadly it looks like just one pcie but the intel NICs look good.