I'm looking for a low power, reasonably priced, supermicro motherboard/processor. Looking for recommendations. Xeon d, atom, whatever. Would like to keep it under 50w total. And under 300$ with the cpu.
It needs at least 1 or 2 8x pcie, bmc, and 6 cores.
pcie v3 and ddr3 are fine.
ok, x the 16x pcie
Really just need to hook up a sas controller, 2+ nvme, a 25/40gbe nic, and possibly a couple of tpu. if it has a built in 10gbe I think that would be enough.
Hmmm...that's going to be kinda tough.
Used prices for Supermicro motherboards have gone up lately, pretty steeply for some models. So the $300 criteria is going to eliminate a whole bunch.
X9/X10 boards with LGA1155/1150 sockets will come in under the price cap, and there's CPU options that can keep consumption under 50w. But they pretty much all lack the PCIe lanes to accommodate all the devices (especially since they don't support PCIe slot bifurcation and there's usually no onboard m.2 slots. So, if you wanted to use that form factor you end up adapters and dedicating a PCie slot for each drive).
Other systems that have enough PCIe lanes and can meet the price point, aren't going to fit the 50w consumption ceiling. Boards with LGA2011, 2011-3, or 2066 for example.
As you note, the stuff that fits the power, price, and connectivity criteria is tending to be well over $300.
Supermicro did make some niche stuff that could work if you're willing to bend criteria and/or compromise a bit. X10SAT, for example, gives you 6 PCIe slots, but three of them are x1 electrically. They'll still work for most of the things you want to connect...but the x1 bandwith is a pretty big limitation. EDIT: Oh, and just remembered that there's no BMC on that one. So, maybe not an option.