Custom Low Power NAS

my suggest: HP ProLiant MicroServer G7 AMD Turion II Neo N54L

I've recently built my NAS with Advantech AIMB-275 motherboard, G4400 CPU and 4GB of RAM, powering it with 12V power brick. It consumes 11W @ idle while running 4TB single HDD, 128GB SATA SSD as boot drive, without fan on CPU cooler (barely gets 40 C, most of the time stays @ 30-ish). I've got this MB for $30 in Poland, but in your country it may be more expensive.

Doesn't Raspberry Pi type of NAS have lower power consumption that that kind of motherboard + CPU?

It's only 2.5-5W for RPI4 depends on a load + whatever your HDD needs (another 3W let's say).

It should be capable to run all what you want.

Just a thought.

This is a great built based on a passively cooled ASRock J5040 Mini-ITX mainboard which I also used for my built. The ASRock J4125 is also a great alternative and I would simply pick one of those based on availability and price. Both mobos should do exactly what you mentioned as a requirement. I used 16 GB RAM for my built but 8 GB should also be fine.

https://www.elefacts.de/test-1…a_und_passiver_4_kern_cpu

Switch to server grade CPUs. They're designed for continous use with power consumption proportional to your usage i.e. they will not burn electricity when all your HDDs are in "Spin down" state. I build my NAS using parts from old junkyard server components and it's been working without any issues (hardware in perticular) for almost a year.

I also used Rpi4 for some time but I don't think their performance is quite satisfactory specially if you intent to use of for anything other then just file server.