Raspberry Pi

Raspberry Pi ( ) is a series of small single-board computers (SBCs) developed in the United Kingdom by the Raspberry Pi Foundation in collaboration with Broadcom. To commercialize the product and support its growing demand, the Foundation established a commercial entity, Raspberry Pi Holdings, a public company that trades on the London Stock Exchange.

The Raspberry Pi was originally created to help teach computer science in schools, but gained popularity for many other uses due to its low cost, compact size, and flexibility. It is now used in areas such as industrial automation, robotics, home automation, IoT devices, and hobbyist projects.

The company's products range from simple microcontrollers to computers that the company markets as being powerful enough to be used as a general purpose PC. Computers are built around a custom designed system on a chip and offer features such as HDMI video/audio output, USB ports, wireless networking, GPIO pins, and up to 16 GB of RAM. Storage is typically provided via microSD cards.

In 2015, the Raspberry Pi surpassed the ZX Spectrum as the best-selling British computer of all time. , 68 million units had been sold.

History

Origins and Launch (2008–2012)

The Raspberry Pi Foundation was established in 2008 by a group including Eben Upton, in response to a noticeable decline in both the number and skill level of students applying to study computer science University of Cambridge Computer Laboratory. The foundation's goal was to create a low-cost computer to help rekindle interest in programming among schoolchildren.

This mission was inspired by the aims of the BBC Micro computer of the early 1980s, which was developed by Acorn Computers as part of a BBC initiative to promote computer literacy in UK schools. The names "Model A" and "Model B" were chosen as a deliberate homage to the BBC Micro. The name "Raspberry Pi" combines the fruit-themed naming convention used by early computer companies with a nod to the Python programming language.The first prototypes resembled small USB sticks. By August 2011, fifty functionally complete "alpha" boards were produced for testing, with demonstrations showing them running a Debian-based desktop and handling 1080p video playback. In late 2011, twenty-five "beta" boards were finalized, and to generate publicity before the official launch, ten of these were auctioned on eBay in early 2012.

The first commercial Raspberry Pi, the Model B, was launched on 29 February 2012, with an initial price of $35. Demand far exceeded expectations, causing the websites of the two initial licensed distributors, Premier Farnell and RS Components, to crash from high traffic. Initial batches sold out almost immediately, with one distributor reporting over 100,000 pre-orders on the first day. The lower-cost $25 Model A followed on 4 February 2013.

The Raspberry Pi did not ship with a pre-installed operating system. While ports of RISC OS 5 and Fedora Linux were available, a port of Debian called Raspbian quickly became the standard. Released in July 2012, it was optimized to leverage the Raspberry Pi's floating-point unit, offering significant performance gains. Raspberry Pi quickly endorsed it as the official recommended OS, and by September 2013, the company assumed leadership of Raspbian's development.

Corporate Evolution

In 2012, the Foundation restructured, creating Raspberry Pi (Trading) Ltd. to handle engineering and commercial activities, with Eben Upton as its CEO. This allowed the Raspberry Pi Foundation to focus solely on its charitable and educational mission. Raspberry Pi (Trading) Ltd. was renamed Raspberry Pi Ltd. in 2021. In June 2024, the company went public on the London Stock Exchange under the ticker symbol RPI, becoming Raspberry Pi Holdings.

Post-Launch Production (2012–2014)

Following the launch, the first units reached buyers in April 2012. To address overwhelming demand and initial supply chain issues, the Foundation ramped up production to 4,000 units per day by July. The first batch of 10,000 boards was produced in factories located in Taiwan and China. A significant strategic shift occurred in September 2012, when manufacturing began moving to a Sony factory in Pencoed, Wales. During this period, the hardware was also refined: the Model B Revision 2.0 board was announced with minor corrections, and in October, its included RAM was doubled to 512 MB.

The post-launch period focused heavily on software and ecosystem development. In August 2012, the Foundation enabled hardware-accelerated H.264 video encoding and began selling licenses for MPEG-2 and VC-1 codecs. A major milestone for the open-source community occurred in October 2012, when the Foundation released the VideoCore IV graphics driver as free software. While the claim of it being the first fully open-source ARM SoC driver was debated, the move was widely praised. This effort culminated in February 2014 with the release of full documentation for the graphics core and a complete source release of the graphics stack under a 3-clause BSD license.

Product Line Expansion (2014–present)

In 2014, the Raspberry Pi product line began to diversify. April saw the release of the Compute Module, a miniature Raspberry Pi in a small form factor designed for industrial and embedded applications, which would soon become the largest market for the computers. In July the Model B+ was released with a refined design featuring additional USB ports and a more efficient board layout that established the form factor for future models. A smaller, cheaper ($20) Model A+ was released in November. A significant leap in performance came in February 2015 with the Raspberry Pi 2, which featured a 900 MHz quad-core CPU and 1 GB of RAM. Following its release, the price of the Model B+ was lowered to $25, a move some observers linked to the emergence of lower-priced competitors.

The Raspberry Pi Zero, launched in November 2015, radically redefined the entry point for computing at a price of just $5. In February 2016, the Raspberry Pi 3 marked another major milestone by integrating a 64-bit processor, Wi-Fi, and Bluetooth. The product line continued to expand with the wireless-enabled Raspberry Pi Zero W (February 2017), the faster Raspberry Pi 3B+ (March 2018), Raspberry Pi 3A+ (November 2018), and Compute Module 3+ (January 2019).

The Raspberry Pi 4, launched in June 2019, represented another major performance leap with a faster processor, up to 8 GB of RAM, dual-monitor support, and USB 3.0 ports. A compute module version (CM4) launched in October 2020. This era saw further diversification with the Raspberry Pi 400 (a computer integrated into a keyboard) in November 2020, and the Raspberry Pi Pico in January 2021. The Pico, based on the in-house designed RP2040 chip, marked the company's first entry into the low-cost microcontroller market. The Raspberry Pi Zero 2 W, introduced in 2021, featured a faster processor, providing a significant performance boost while maintaining the low-cost, compact form factor.

The global chip shortage starting in 2020, as well as an uptake in demand starting in early 2021, notably affected the Raspberry Pi, causing significant availability issues from that time onward. The company explained its approach to the shortages in 2021, and April 2022, explaining that it was prioritising business and industrial customers.

The Raspberry Pi 5 was released in October 2023, featuring an upgraded CPU and GPU, up to 16 GB of RAM, a PCIe interface for fast peripherals and an in-house designed southbridge chip. Updated versions of the Compute Module (CM5) and keyboard computer (Pi 500) based on the Pi 5's architecture were subsequently announced. The Raspberry Pi Pico 2, released in 2024, introduced the RP2350 microcontroller, featuring selectable dual-core 32-bit ARM Cortex-M33 or RISC-V processors, 520 KB of RAM, and 4 MB of flash memory.

Sales Milestones

The Raspberry Pi's sales demonstrated remarkable growth. The one-millionth Pi was sold by October 2013, a figure that doubled just a month later. By February 2016, sales reached eight million units, surpassed the ZX Spectrum as the best-selling British computer of all time. Sales hit ten million in September 2016, thirty million by December 2019, and forty million by May 2021. As of its tenth anniversary in February 2022, a total of 46 million Raspberry Pis had been sold. , 68 million units had been sold.

Series and generations

There are five main series of Raspberry Pi computers, each with multiple generations. Most models feature a Broadcom system on a chip (SoC) with an integrated ARM-based central processing unit (CPU) and an on-chip graphics processing unit (GPU). The exception is the Pico series, a microcontroller which uses the RP2040, a custom-designed SoC with an ARM-compatible CPU but no GPU.

Flagship series

The flagship Raspberry Pi series, often referred to simply as "Raspberry Pi", offers high-performance hardware, a full Linux operating system, and a variety of common ports in a compact form factor roughly the size of a credit card.
* The Model B (2012) features a 700 MHz single-core 32-bit ARM11 CPU, a VideoCore IV GPU, 512 MB RAM and a 26-pin GPIO header.
* The Model A (2013) is a lower-cost version with 256 MB RAM, no Ethernet, and fewer USB ports.
* The Model B+ and Model A+ (2014) add a 40-pin GPIO header, microSD card support, and replace the RCA video connector with a combined 3.5 mm audio/video jack.
* (2015) includes a 900 MHz quad-core Cortex-A7 CPU and 1 GB of RAM.
* (2016) features a 1.2 GHz quad-core 64-bit Cortex-A53 CPU, Wi-Fi, Bluetooth, and USB boot support.
* The Raspberry Pi 3 Model B+ (2018) upgrades to a 1.4 GHz CPU, faster Ethernet, dual-band Wi-Fi, and Power over Ethernet (PoE) support.
* The Raspberry Pi 3 Model A+ (2018) is the final A-series model, offering the same features as the 3B+, but with 512 MB RAM and in a smaller form factor.
* (2019) introduces a 1.5 GHz quad-core Cortex-A72 CPU, a VideoCore VI GPU, USB 3.0 ports, true Gigabit Ethernet, support for dual 4K monitors, and options for 1, 2, 4, or 8 GB of RAM.
* (2023) features a 2.4 GHz quad-core Cortex-A76 CPU, a VideoCore VII GPU, PCIe support, and options for 2, 4, 8, or 16 GB of RAM. It omits the 3.5 mm audio/video jack.

Keyboard series

The Keyboard series combines Raspberry Pi hardware and ports into a keyboard computer form factor, providing a self-contained Linux-based desktop system.
* The Raspberry Pi 400 (2020) features a custom board based on the Pi 4. It includes a 1.8 GHz quad-core Cortex-A72 processor, 4 GB of RAM, and a large integrated heat sink. It supports dual 4K monitors via two micro HDMI ports and includes gigabit Ethernet.
* The Raspberry Pi 500 (2024) is based on the Pi 5 and succeeds the Pi 400. It features a 2.4 GHz quad-core Cortex-A76 processor and 8 GB of RAM. Unlike the Raspberry Pi 5, it lacks a PCIe interface.

Zero series

The Raspberry Pi Zero series are compact, low-cost, and low-power single-board computers that provide basic functionality and Linux compatibility for embedded and minimalist computing applications.
* The Raspberry Pi Zero (2015), priced at US$5, features a 1 GHz single-core ARM11 CPU, 512 MB of RAM, mini HDMI, and micro USB ports for data and power. It includes an unpopulated 40-pin GPIO header.
** The Zero v1.3 (2016) added a camera connector.
** The Zero W (2017) introduced onboard Wi-Fi and Bluetooth for US$10.
** The Zero WH (2018) added pre-soldered GPIO pins for US$15.
* The Raspberry Pi Zero 2 W (2021), priced at US$15, features a quad-core 64-bit ARM Cortex-A53 CPU and includes wireless connectivity. The Zero 2 WH variant adds a pre-soldered GPIO header for US$18.

Pico series

The Pico series are compact microcontroller boards based on Raspberry Pi-designed chips. Unlike other models, they do not run Linux or support removable storage, and are instead programmed by flashing binaries to onboard flash memory.
* The Raspberry Pi Pico (2021) was the first board based on the in-house RP2040 microcontroller. It features a dual-core 32-bit ARM Cortex-M0+ CPU, 264 KB of RAM, and 2 MB of flash memory, priced at US$4. The Pico W (2022) adds Wi-Fi and Bluetooth and launched at US$6. The board has a castellated edge for direct soldering to a carrier board; versions are available with pre-soldered, bottom-mounted header pins, the Pico H for US$5 and the Pico WH for US$7.
* The Raspberry Pi Pico 2 (2024) introduced the RP2350 microcontroller, featuring selectable dual-core 32-bit ARM Cortex-M33 or RISC-V processors, 520 KB of RAM, and 4 MB of flash memory, priced at US$5. The Pico 2 W adds Wi-Fi and Bluetooth for US$7.

Compute Module series

The Compute Module (CM) series delivers Raspberry Pi's flagship hardware in a compact form for industrial and embedded applications, omitting onboard ports and GPIO headers in favour of a carrier board interface. Compute Modules are offered in one of two formats: a board matching the physical dimensions of a DDR2 SO-DIMM RAM module (though electrically incompatible with standard SO-DIMM sockets) and a smaller board with dual 100-pin high-density connectors that enables additional interfaces.
* Compute Module 1 (2014) – Based on the original Raspberry Pi. Features a single-core ARM11 CPU, 512 MB RAM, and 4 GB eMMC flash storage. SO-DIMM form factor.
* Compute Module 3 (2017) – Based on the Pi 3. Includes a quad-core 64-bit Cortex-A53 CPU, 1 GB RAM, and 4 GB eMMC; also available as a "Lite" variant without eMMC. SO-DIMM form factor.
* Compute Module 3+ (2019) – Based on the Pi 3+. Offers 0 (Lite), 8, 16, or 32 GB eMMC options. SO-DIMM form factor.
* Compute Module 4 (2020) – Based on the Pi 4. Includes a quad-core 64-bit Cortex-A72 CPU, 1, 2, 4, or 8 GB RAM, and 0 (Lite), 8, 16, or 32 GB eMMC; optional Wi-Fi and Bluetooth. High-density connector form factor; CM4S variant uses SO-DIMM form factor.
* Compute Module 5 (2024) – Based on the Pi 5. Features a quad-core 64-bit Cortex-A76 CPU, 2, 4, 8, or 16 GB RAM, and 0 (Lite), 16, 32, or 64 GB eMMC; optional Wi-Fi and Bluetooth. High-density connector form factor.

Model/series comparison table

Notes

Hardware

Since its introduction, Raspberry Pi hardware has been designed to provide low-cost computing platforms. The founders intended it to be an affordable and accessible system by making it compatible with widely available second-hand peripherals, such as televisions for displays, USB input devices, and cellphone chargers for power. Over time, the hardware has expanded to support both advanced configurations and ultra-low-cost variants. The company has also committed to keeping products in production for up to ten years.

The Raspberry Pi has undergone multiple hardware revisions, with changes in processor type, memory capacity, networking features, and peripheral support. All models include a processor, memory, and various input/output interfaces on a single circuit board. Most include an HDMI output, USB ports, and a GPIO (general-purpose input/output) header. Networking capabilities vary by model, with later versions featuring integrated Wi-Fi and Bluetooth. Storage is typically provided via a microSD card, with newer models supporting USB or PCIe-based boot options.

Processors and system-on-chip

Raspberry Pi models use a range of system on a chip (SoC) designs, developed in partnership with Arm and Broadcom. Each generation has introduced improvements in CPU architecture, clock speed, graphics, and overall performance.

The original Raspberry Pi and the Pi Zero use the Broadcom BCM2835, featuring a single-core 32-bit ARM11 CPU and a VideoCore IV GPU. The CPU is clocked at 700 MHz on the original Pi and 1 GHz on the Zero and Zero W.

The Raspberry Pi 2 introduced the BCM2836 with a 900 MHz quad-core 32-bit Cortex-A7 CPU, while later revisions used the 64-bit BCM2837 with Cortex-A53 cores. The Raspberry Pi 3 retained the BCM2837, increasing the CPU clock to 1.2–1.4 GHz depending on the model. The Pi Zero 2 uses the RP3A0, a system in a package (SiP) combining the quad-core Cortex-A53 processor clocked at 1 GHz with 512 MB of RAM.

The Raspberry Pi 4 introduced the BCM2711, a 64-bit SoC with a quad-core Cortex-A72 CPU and VideoCore VI GPU. Clock speeds were initially 1.5 GHz and later increased to 1.8 GHz. The Raspberry Pi 5 uses the BCM2712, featuring a quad-core Cortex-A76 CPU at 2.4 GHz, an 800 MHz VideoCore VII GPU, and a separate RP1 southbridge chip designed in-house.

Raspberry Pi has also developed its own chips outside of its partnership with Broadcom. The Raspberry Pi Pico uses the RP2040, featuring dual-core 32-bit Cortex-M0+ processors running at 133 MHz and 264 kB of on-chip RAM. The Pico 2 uses the RP2350, which can operate with either dual-core Cortex-M33 or dual-core Hazard3 RISC-V CPUs selected at boot, running at 150 MHz, with 520 kB of RAM.

Overclocking

Most Raspberry Pi models support user-configurable overclocking through the system configuration file. More recent models feature dynamic frequency scaling, adjusting CPU speed based on workload to balance performance and thermal output. This behavior, while similar to overclocking, is part of the default power management system. If the CPU temperature exceeds or if undervoltage is detected, performance is throttled automatically. For sustained high-performance workloads, additional cooling—such as a heat sink or fan—may be required.

RAM

The original Raspberry Pi Model B was equipped with 512 MB of random-access memory (RAM), which, like later models, shares memory between the CPU and GPU. All Raspberry Pi boards support dynamic memory allocation between these components, allowing the system to adjust the division based on workload or user configuration. The original Model A included 256 MB of RAM.

Subsequent models introduced increased memory capacities. The Pi 2B and 3 B/B+ models feature 1 GB of RAM, while the smaller 1A+ and 3A+ models have 512 MB. The Pi Zero and Zero 2 W also include 512 MB. The Pi 4 is available with 1, 2, 4, or 8 GB of RAM, and the Pi 5 expands this further with options for 2, 4, 8, or 16 GB, the highest capacity offered to date.

Storage and peripherals

Storage is typically provided via a microSD card, though some Compute Modules offer onboard eMMC flash. Newer models support USB booting, and the Pi 5 includes support for NVMe SSDs over PCIe.

Boards also include USB ports for peripherals such as keyboards, mice, and storage devices.

Video

Raspberry Pi devices support both digital and analog video output across various resolutions.

Early models featured a full-size HDMI port and an RCA connector for analog composite video output. Later boards removed the RCA jack but retained analog output via the 3.5 mm TRRS jack or dedicated solder points. According to the Raspberry Pi Foundation, analog support helps maintain accessibility in developing countries.

To accommodate the addition of features on the compact boards, video connectors have shrunk across models. The Pi Zero series uses a mini-HDMI connector, while the Pi 4 and 5 use dual micro-HDMI ports. This change enables support for multiple displays: the Pi 4 can drive two 4K displays at 30 Hz or one at 60 Hz, while the Pi 5 improves on this with support for two 4K displays at 60 Hz.

Older Raspberry Pi models support common display resolutions such as 720p and 1080p by default, with some capable of higher resolutions depending on hardware and configuration. In some cases, older hardware can output in 4K, though performance may be poor.

GPIO header

Most Raspberry Pi models include a 40-pin connector known as the GPIO (general-purpose input/output) header, although only some of the pins are dedicated to GPIO functions. The header, designated as J8, uses a consistent pinout across models.

The header supplies 3.3 V and 5 V power along with various multiplexed, low-speed interfaces, including UART, SPI, I²C, I²S, and PCM. GPIO pins can be configured as either inputs or outputs. When set as an output, a pin can drive a high (3.3 V) or low (0 V) signal. When configured as an input, it can read a high (3.3 V) or low (0 V) voltage level.

The original Raspberry Pi 1 Model A and B include only the first 26 pins of this header. On some Pi Zero models, the header is unpopulated, but solderable through-holes are provided. The Pico models feature a unique layout with unpopulated through-holes and a castellated edge, allowing it to be surface-mounted as a module. Compute Module boards do not include GPIO headers but instead expose GPIO signals through their board connectors.

Networking

Networking capabilities differ by model. The Model B and B+ include an Ethernet port. Starting with the Raspberry Pi 3, most models come with built-in WiFi and Bluetooth. The Raspberry Pi 3B+ adds faster Ethernet and dual-band WiFi. The Raspberry Pi 4 and 5 offer full gigabit Ethernet. The "A" models and the Pi Zero series do not have Ethernet ports, and built-in wireless support is optional. A USB adapter may be used for wired or wireless connections.

Special-purpose features

Some Raspberry Pi models, like the Zero, 1A, 3A+, and 4, can act like a USB device (via the USB On-The-Go protocol) when plugged into another computer. This lets them work as gadgets such as a virtual keyboard, network adapter, or serial device.

Many newer models can also start up (or "boot") directly from a USB drive, without needing a microSD card. This feature isn't available on older models like the original Raspberry Pi, Pi Zero, or early versions of the Pi 2.

Real-time clock

Most Raspberry Pi models do not include a built-in real-time clock, which means they rely on an internet connection to set the correct time with the Network Time Protocol when they start up. If there's no connection, the time must be set manually or the system assumes no time has passed since it was last used. Add-on clock modules are available for situations where accurate timekeeping is needed without internet access. The Raspberry Pi 5 is the first model to include a built-in clock which uses a battery to keep time when powered off.

Board layouts

File:Drawing of Raspberry Pi model B rev2.svg, Pi 1B v1.2
File:Raspberry Pi 1A.svg, Pi 1A
File:Drawing of Raspberry Pi model A+ rev1.1 (cropped).svg, Pi 1A+ v1.1
File:Raspberry Pi B+ rev 1.2.svg, Pi 1B+ v1.2 and Pi 2
File:RaspberryPi 3B.svg, Pi 3
File:RaspberryPi 3B%2B.svg, Pi 3+
File:RaspberryPi Model 4B.svg, Pi 4
File:RaspberryPi 5B 28-08-2024.svg, Pi 5

Software

Operating systems

The recommended operating system is Raspberry Pi OS, a Debian-based Linux distribution optimized for Raspberry Pi hardware and tuned to have low base memory requirements. It is available in both 32-bit and 64-bit versions and comes in several editions: a standard edition, a "Lite" version without a desktop environment, and a "Full" version that includes a comprehensive suite of software.

Raspberry Pi OS can be purchased pre-installed on a microSD card, or downloaded and installed using Raspberry Pi Imager, a utility introduced in March 2020 to simplify the installation of operating systems onto SD cards and other media for Raspberry Pi devices. Available for macOS, Raspberry Pi OS, Ubuntu, and Windows, Imager allows users to download and write operating system disk images within a single application. In addition to Raspberry Pi OS, the utility supports a variety of third-party operating systems, including Alpine Linux, Android, Armbian, FreedomBox, Kali Linux, LibreELEC, RetroPie, RISC OS, SatNOGS, and Ubuntu.

Firmware

The Raspberry Pi uses official firmware that is proprietary

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