Microsoft announced its unusual Surface Hub concept way back in January 2015 as a new breed of business computer. These were to be huge 84-inch or 55-inch all-in-one PCs with multi-touch functionality - ideal for office presentations and video conferences.
As noted, the Surface Hub comes in two sizes, 55-inch and 84-inch. Both support 100 points of touch input, as well as stylus input.
The Microsoft Surface Hub family runs on an Intel Core i5 or i7 CPU backed by 8GB of RAM, and features a 128GB SSD. The 84-inch model also boasts a discrete Nvidia Quadro graphics card, which helps drive its large 4K display (the 55-inch model is 1080p).