The Entry level general purpose computer is probably now the Raspberry Pi or equivalent BeagleBone computer.
But whilst these computers can be used almost ad infinitum for small home automation projects if you need something larger what would you choose?
For example for a Home Network Attached Storage, or Home Surveillance System. Or perhaps a high throughput Firewall or Media Centre.
In these cases I would strongly recommend you consider an Asrock ITX mainboard in a suitable case.
The Overall Plan
+ The AsRock ITX computers use Intel CPU's so run off the shelf Linux, Windows, Firewall Software. There is a vast selection. I've even had mine running Windows 2012 Storage Server, or in a recent test Windows 2016 server!
= I'd suggest a Corsair 240 case which has a brilliant design (I'll cover it another day) if you are planning to construct a reliable 24x7 system
+ They fully support UEFI boot
+ A Plethora of USB 3 and SATA 6GB/s ports
+ A PCIe 2.0 x1 expansion slot
+ DVI and Displayport and HDMI outputs. Can drive 4K monitor and more than 1 monitor
+ Upto 16GB memory in 2 DDR3 slots
+ Bonkers 71 HD Audio
+ Room for a Mini PCIe slot so you can add Bluetooth
+ Modern features like GUI based BIOS and firmware updates via Internet download, secureBoot etcetera
The killer selling point though is that the mainboard includes the Intel N3700 CPU and heatsink: no fan is required. So you don't need to factor in the cost of a separate cooler or CPU. Just add memory and a Power Supply and basically you can start.
This makes for a really cost effective appliance that is several steps up from a Raspberry Pi.
Mini ITX vs Micro ATX
I am relatively new to the ITX mainboard / motherboard format. The biggest surprise to me is that Mini ITX is smaller than Micro ATX.
Mini-ITX 17cm x 17 cm
Micro-ATX 24.4 x 24.4 cm
Mini-ITX has spawned a whole series of much cheaper cases. In a way my suggestion of using the Corsair 240 leads to quite an expensive built. But trust me, the 240 is very flexible and you can put together a fantastically stable, cool running unit that I think warrants the extra outlay over the ITX only case.
A new Model
I have been using this as a general purpose project PC since April 2016 and now find there is a slightly newer model
To give you an indication this is about 130 CHF in Switzlerland. And the new model is Quad Core!
I'm about to put this computer into service as an upgraded Firewall to the current Zyxel and Sophos firewalls that we currently use. Stay put for an in depth discussion soon.
AsRock J3710-ATX At Digitec