The Intel NUC proves just how small a desktop-class, 4K-capable Haswell PC can go. What the NUC doesn't do, though, is let us switch out the processor - it comes with either a Core i3 or i5 soldered to the mainboard. Now, Shuttle's DS81 is slightly bigger than the NUC, but it's still tiny (19 x 16.5 x 4.3cm) and its H81 chipset supports user-upgradeable processors up to a Haswell Core i7. Like the DS61 before it, the DS81 comes with serious cooling to let it function in environments up to 50 degrees Celsius, such as in digital signage situations. It's also deceptively big in terms of connectivity, with two PCIe Mini slots (one half-size and one full-size), two slots for RAM (up to 16GB), six USB ports (two of which are 3.0), three displays outputs (1x HDMI and 2x DisplayPort), dual Gigabit Ethernet ports and even a card reader. A Shuttle rep we met at CeBIT told us the DS81 should start to become available from next week, starting at 178 euros ($250) for a barebones unit - although some retailers are already offering pre-built systems for upwards of $800 with a two- or three-week shipping delay.