This is my low power home NAS server build. Having it consume as little power as possible was top priory since it will be on 24/7. Pulls 15W at idle with the hard drives spun down and about 25W when in use. I am using a 80 Plus Gold rated power supply. Definitively not a power house but plenty fast fore a simple home server. It runs Windows 10 off a live flash drive. The J4205 board has an embedded fan less CPU and the power supply fan doesn't kick on until it reaches a certain amount of draw (has yet to kick on and doubt it ever will). Nice if you are worried about the noise. Only two hard drives for now. More will be added later. The board its self only has 4 sata ports. I plan to buy a 4 sata port card for the one PCIe 1x slot when I have the need for more drivers. The plan is to run the 4 main hard drivers off the motherboards sata ports and the four backup drivers off the PCIe card ports. Overall very happy with the build. Very low power consumption and room to add more drives in the future.
Updated Fall 2018. Swapped the USB stick for a real SSD. Bought the Silicon Power drive used on ebay for $15. Also added an old 120GB 2.5" sata HHD to use as a scratch drive for commonly used files. That way the main drives don't need to spin up to grab a word doc I use everyday. I purchased two more Western Digital drives. Both are 4TB. I added in a PCIe 1x card which added 4 more sata ports. I have the backup drives connected through the PCIe card so generally only one is being used at a time.