pi4

pi4 commonly refers to the Raspberry Pi 4 Model B, a low-cost single-board computer developed by the Raspberry Pi Foundation. It is the fourth generation in the Raspberry Pi line and was released in 2019. The Pi 4 marked a major architectural update over earlier models, offering more memory, improved I/O, and enhanced network connectivity to enable more desktop-like usage and a wider range of projects.

Hardware specifications include a Broadcom BCM2711 quad-core Cortex-A72 processor running at 1.5 GHz, and memory options of 1 GB, 2 GB, 4 GB, or 8 GB of LPDDR4-3200 RAM. It uses the VideoCore VI graphics processor and provides a microSD card slot for storage. The board supports dual micro-HDMI outputs capable of a combined 4Kp60 display, and it retains the familiar GPIO header for peripherals and expansion.

Connectivity and input/output features include Gigabit Ethernet, 802.11ac Wi-Fi, and Bluetooth 5.0. It offers two USB 3.0 ports and two USB 2.0 ports, a USB-C power input (recommended 5V at 3A), dual micro-HDMI connectors, and camera interfaces (CSI and DSI) for external sensors and displays.

Software and usage revolve around Raspberry Pi OS (formerly Raspbian), with support for many Linux distributions such as Ubuntu, as well as specialized builds for media centers, retro gaming, and embedded projects. Common applications include education, home servers, media streaming, DIY robotics, and edge computing.

Variants and evolution notes include the initial RAM configurations and the later addition of an 8 GB model. Early production faced a USB-C power connector issue that was addressed in subsequent revisions, along with ongoing improvements in power management and thermals.