I was very close to buying a new mini PC a few months ago as for I wanted a low cost and low power consumption x86 or x64 NAS that also ran mySQL for my database testing and socket connection testing with scripts etc that interface with a database.
I looked at the mini PC's and what I needed and realized that repurposing my old Toshiba Netbook bought in 2009 with Intel Atom processor and 2GB RAM was the best solution for me. The Intel Atom APU based netbook operates on 13 watts of continuous power draw and runs cool. It is running Windows XP Home SP3 32-bit which is the OS that it came with.
I was on the search for a low power consumption x86 or x64 based computer, but many of the mini PC's that supported the x86 or x64 OS and programs ran on 19 watts or greater power consumption. I was hoping to find a mini computer that was in the 5 watt range drawing close to a night light bulb of power and able to act as a NAS as well as have a MySQL database running 24/7/365. What i found when looking is that in order to get to that low of a power draw I need to cross over from x86 and x64 CPU or APU's to ARM processors, but that might work for making a NAS but it wouldnt be hosting a MySQL server. So I threw in the towel on going to a more power efficient setup beyond that of the Intel Atom 1.66Ghz Netbook.
Prior to this Netbook I was running a AMD Athlon 2650e 1.6Ghz 15 watt TDP single-core desktop tower, but the tower itself was drawing 31 watts continuous. When i dug out my Netbook and tested its power draw and saw that it was just 13 watts I decided to migrate everything over to that. It would be nice to get to around 5 watts of power draw and have what i need but I just dont see that happening at this time, then comes the ratio of saving 8 watts of power would come at what cost. Electricity is 15 cents per kWh and so daily consumption is equal to 312 Watts or .312 kW and a cost of just ( 4.62 cents ) and if I can get to 5 watts it drops the daily cost to 1.8 cents to run it which would be a 2.82 cents less power consumption which is an annual savings of $10.29 . So to break even if a Mini PC cost me $100 would take almost 10 years to recoup the cost of going lower in power draw, so I've hit the wall where 13 watts will have to do for now I guess.
Lastly its beneficial to the netbook or a laptop to be handling this role as for if there is a dip in power it will run off the battery. And if there is an outage it will run for as long as the battery can keep it up and at 12% power it shuts down safely to not corrupt itself, whereas a modern Mini PC would require a battery backup to give data protection like this at additional cost. So an old laptop or netbook that otherwise is too limited to be used for daily computing could be repurposed as a mini PC server and low cost of operation and setup.
