It depends on the SoC used. Some will have 1 or 2 SATA controllers on board. This board is based on the Exynos 4412 which I don't think has SATA controllers o

It depends on the SoC used. Some will have 1 or 2 SATA controllers on board. This board is based on the Exynos 4412 which I don't think has SATA controllers on board (can't find a full datasheet). This means adding them externally, not big deal right? But, 99% of SATA controllers today are built to talk PCI-Express, and the Exynos SoC doesn't speak PCI-Express! We're screwed... Basically the same thing happens with gigabit Ethernet (and USB 3.0). Unless the SoC has the controller on-board or has PCI-Express (few do) there really isn't a way to plug the external controller into the SoC. 10/100 Ethernet is slow enough that you can pump its data in and out of the SoC using a SPI port and get most of the speed and many SoCs now have a 10/100 controller and USB 2.0 controllers on board. There is no spec limit to the speed of SPI but its a single ended 2 wire protocol limiting its realistic usage to the several tens of Mbit/sec. The problem is that there is no commonly accepted, generic, very high speed I/O protocol for embedded devices so if they choose not to implement PCI-Express your left without a way to pump information into and out of the SoC at fast enough speeds to support these new interfaces.