Gigabyte has a superb range of their mini PCs they call the Brix. If you have never seen a Gigabyte Brix PC , you really won’t believe how small they are. The range is extensive and covers Intel Celeron, core I3, core I5, and core and core I7 versions. Every unit comes with a vesa bracket allowing it to attached to the back of a suitable monitor, for an “all in one PC” like setup.
Most Gigabyte Brix mini PC come in a standard and a H version (H in the code). For example the core I3 unit comes as GB-BRI3-10110 & the GB-BRI3H-10110 The standard models are shorter in height, and take msata solid state hard drive. An msata drive looks like a piece of memory, these come in sizes up to 240GB, but a significantly smaller than 2.5” solid state hard drives, and so are better suited to tiny chassis. The H versions can also take a msata drive, but the extra height also allows them to take a 2.5” drive. So you can have 1 or 2 drives installed. This combination works particularly well when you want a small high speed drive for windows itself and common applications you use, then a second 2.5” large for storage. This makes a lot of sense as solid state drives are much more expensive than standard 2.5” drives per GB.
All the units are have 2x sodimm memory slots, and most support up to 64gb. More basic processor version, some of which are fanless are also available.
Below is one of the Celeron units, the Gigabyte Brix GB-BMCE-4500C
The tiny size makes them very useful as a commercial “out of the way” PC, as their power allows them to handle many commercial applications such as digital signage, EPOS etc.