Aloha,
So far, I'm running an ASRock E350M1 with an E-350 (dual core 1.6GHz), 8GB DDR3, 3 drives (ranging from 1.5 to 4TB), and the OS sits on an Intel SSD 120. It’s sluggish—and pulling about 55W while running. I’m using Windows Server 2016 with one VMware VM running Windows 10 32-bit. Everything works, sure, but man, it crawls. It’s not a total disaster, but it's annoying as hell.
I’ve been eye-balling the ASRock J4205-ITX which packs a Pentium J4205 (quad core up to 2.6GHz)
http://www.asrock.com/mb/Intel/J4205-ITX/What’s the verdict? People over here say power draw hits 17W at 100% CPU load. Even running just Linux with a single drive or maybe even just a USB stick, it still pins the CPU at 100%.
Most of my drives stay in sleep mode, but let's say all three are cranking away—that's maybe another 15W. Total would be around 32W. Still a solid 20W drop compared to my current setup.
The only thing missing on this new board is an M.2 slot for an extra drive (it has an M.2 slot, but only for a WiFi card, which I don't need)—not a dealbreaker, though...
Anything else I should be looking at?