DIY Low power NAS, is it just a dream?


For a long time I have been trying to develop this idea of building a low power NAS, something like a synology that would be connected 24/7, but with no sucess.

every time I see the consumption for only the CPU I get scared, my ideal consuption shouldn’t be greater than 50W average, probably 20-30 W idle for the complete system.

Is this just a dream?

I could go ARM but I would like the x86 flexibility, I would probably run a couple more services on the NAS, like Docker, I would also like the chance to connect 5 drives for dual redundancy.

It seems the solution is the laptop CPU but I don’t any with so many drives.

does this exists or there are other solutions?

Thanks for the help!

Have you looked at sbc, the raspberry pi 4 sounds perfect for a use case like this

And the rockpro64 seems even better.

And a x86 system could it do it? Or there isn’t much different on the software available for one or the other.

Perhaps a arm CPU is the way forward, I would to have more options.

If you’re doing pure file storage ARM can operate just fine (look at the low end synology)

But “low-power” means a variety of things to a variety of people.

Link Here’s a link that shows rough power usage for a WD Red 4tb. (First google result for hard drive power consumption) which shows between ~3-5W.

Do you want low power for heat reasons? operating price reasons? something else?

Prep for some rough n ready napkin math

Power Consumption Calculation

E (kWh/day) = P (W) × t (h/day) / 1000(W/kW)

kWh Calculator Link

Power Rates (listed by state avg)

Link Using this as a basis for calculation of cost.

Begin Napkin

100 W Nas = 876 kwh a year

Assuming you live in HI (highest listed), that costs you (avg price used 29.18c per kwh) = $255.62 (rounded up to nearest cent). This equates to $0.70 a day.

Assuming you live in LA (lowest listed), that costs you (avg price used 7.71c per kwh) = $67.54 (rounded up to nearest cent). This equates to $0.19 a day.

This assumes flat 100w usage 24/7/365. Your idle may be higher or lower depending on configuration/hardware/location/etc. If you spin down disks at idle, this also changes the calculus.

Just be wary of doing something like spending $200 to “save” money on utilities. That power “savings” costs you $0.55 a day (during the first year) in which you will still be paying utilities. Other options include spending more on higher-density disks to reduce power consumption.

End Napkin

Sample Cost Calculation

To give you a sample, I run a (comparatively older than a lot of folks) dual x5670 build with 20 hard drives, 1 ssd cache drive. No spindown, on 24/7/365. Using local (Michigan’s 2019 avg) rate = 15.82c per kwh

Usual “idle” usage = ~315W (as measured by UPS, including all other connected devices) == $436.54 a year === $1.20 a day
Usual “full transcode” (plex optimization of media) ~400W == $554.33 a year === $1.52 a day


Just be aware if you steer towards something on an alternate architecture for power reasons you may be limited to what you can do with your NAS. In the end it’s up to you to run the numbers and see what is possible with your setup. If you’re going pure NAS it’s a good option, but if you run ANYthing else, you may really want something better than an ARM chip.

Play around with the calculators and see what you come up with! Hopefully this was helpful for you and others.


The low t is because of both.

More heat means more energy to dissipate that will introduce even more operational cost.

That’s why I’m looking more for the x86, to do more like the high end Synology.

This seems to be directly opposite of your original post. “Because of both” just means you haven’t defined which is more important.

How many bays? How many apps running? anything special going on? All going to influence the factors.

I don’t think so, I need to deal with more heat and it normally means more power consumption normally with the the use of fan’s that will increase the cost even more.

Less power -> less heat -> less money spent in cooling.

in term of bays, my ideal would be 5, two have two drive failure tolerance and still be able to have space and performance.

in apps, I don’t know yet, but probably, 5-6 apps running

But cooling isn’t what everyone spends the big bucks on so reducing heat to save on cooling products doesn’t seem to stack up.

I think faultine nailed it in his post. I’d suggest thinking long and hard about what your real goals are, for what reason, and how much are you really willing to pay for it (or sacrifice).

Sometimes when you break it down on paper it just doesn’t make economical sense. There’s a reason no one pays for triple pane windows in the south.

I’ve always wanted to try and make a low power NAS too. I thought about using a SFF computer by attaching a DAS via a SAS PCI-E card.

There are better people here to explain this but you have to look at it as a performance per watt.

At present I’m still a noob on my Unraid setup…gathering parts and building as I go. I’ve got a Windows 10vm running, dockers (AirConnect, Remmina, Syncthing, Filezilla, Zerotier, and ClamAV) with 6.5tb of hdd storage with parity and 250gb of ssd cache. This runs on a 4c 8t xeon 1240 v2 and the motherboard is a Supermicro X9SCL. My APC ups says I’m running at 138 watts, normally it’s around 112 watts. Basically that’s probably a lot of wattage for no more than I’m running. I could reduce that wattage by higher density drives and probably will at some point in the future when I feel the need. The more I add to this the more power it consumes so at some point yes I’d like to go the other direction to cut down on power draw. You can accomplish some of this by building a machine that does more like say virtualize pfSense, have a Plex server instead of a quicksync box…that alone probably cuts out a good 40 watts roughly for me…but I would rather have separate boxes for those tasks. This doesn’t even get into some of the hidden power costs like running battery backup…I’ve got one that pulls about 50 watts with nothing plugged in…It’s a enterprise grade UPS. I don’t need it but I paid like 10 bucks for it so I’m going to get some use out of it.