Raspberry Pi 2 unveiled with more memory and faster processor
A new version of the Raspberry Pi single-board computer has been unveiled in London today, boasting more memory and a new processor that is six times faster than its predecessor. The Raspberry Pi 2 is available to buy today from element14, priced at $35. It is the same size as the previous version, but comes with a Broadcom BCM2836 ARMv7 quad core processor, and runs at 900MHz with 1GB of RAM. It offers complete backward compatibility with the existing Model B+. All cases and third-party add-on boards are also fully compatible with the new Raspberry Pi. The new model has an expanded number of input/output pins, making it possible to connect up to four USB devices - including some powered devices such as hard drives - as well as multiple sensors, connectors and expansion boards.
However, Raspberry Pi faces growing competition. Rivals include the Arduino, Intel Galileo, Gizmo 2, BeagleBone Black and Hummingboard.
For example:
Ardiuno is based on a microcontroller, there is no "real" OS apart from some specialised microcontroller OS' like RTOS. Apart from Due (84MHz) all other MCUs are 16MHz or slower. RAM and internal flash memory is in the order of KB.
On the other hand all other boards you listed are running proper OS (linux/windows), all have frequencies in the range of 1GHz, RAM is external and is in the order of GB. Memory is usually on a separate chip from the CPU, for example on memory cards or eMMC flash.