NOTE: Previous versions of Raspberry Pi 2 Model B use the BCM2836 SoC, which contains a quad-core ARM Cortex-A7 processor. The Raspberry Pi 2 Model B v1.2 board uses BCM2837, which contains a quad-core ARM Cortex-A53 processor. It is necessary to update to the latest (October 2016) version of the device firmware and Linux kernel to allow the board to boot up properly.
Compared to the Model B it has:
More GPIO pins. The GPIO header has grown to 40 pins, while retaining the same pinout for the first 26 pins as the Model A and B.
More USB ports. It comes with 4 USB 2.0 ports, compared to 2 on the Model B, and better hotplug and overcurrent behaviour.
Micro SD. The old friction-fit SD card socket has been replaced with a much nicer push-push micro SD version.
Lower power consumption. By replacing linear regulators with switching ones we’ve reduced power consumption by between 0.5W and 1W.
Better audio. The audio circuit incorporates a dedicated low-noise power supply.
Neater form factor. We’ve aligned the USB connectors with the board edge, moved composite video onto the 3.5mm jack, and added four squarely-placed mounting holes.
