The original Raspberry Pi is based on the Broadcom BCM2835 system on a chip (SoC),[2] which includes an ARM1176JZF-S 700 MHz processor, VideoCore IV GPU,[9] and was originally shipped with 256 megabytes of RAM, later upgraded (models B and B+) to 512 MB.[3][10] The system has Secure Digital (SD) (models A and B) or MicroSD (models A+ and B+) sockets for boot media and persistent storage.[11]