An energy friendly HTPC or a monster gaming gaming PC: with the latest generation of mini ITX motherboards anything is possible in a small form factor case. We tested a total of 15 ITX boards for Intel Haswell processors, in a price range of 50 to 200 pounds.
The very compact Mini-ITX format is becoming more popular, not least because of the wide variety of available small form factor cases. There is no reason why you should not consider a smaller PC, as the latest ITX motherboards all support the newest Core i5 and i7 Haswell processors, while in a lot of smaller cases there is enough space for a high end (dual slot) graphics card. This will enable you to build a small PC that equals the performance levels of a much larger (micro) ATX system. Manufacturers are catching on to this trend and have introduced mini-ITX boards with all features you find on their bigger counterparts.
Originally ITX boards were widely used for low power HTPC systems, industrial systems and smaller business PC's, but also as a base for building a home server or a NAS. The size of the boards (17 x 17cm) means that they are still very well suited for applications like this.