What is the Raspberry Pi 4? Everything you need to know about the tiny, low-cost computer

An introduction to the Raspberry Pi 4 Model B computer, from how to set it up, to what you can do with it.

Turning a Raspberry Pi computer into an air monitoring station with a few add-ons Pimoroni's Enviro+ Raspberry Pi hat lets you start to measure the quality of air around your home.

WHAT IS THE RASPBERRY PI 4?

The Raspberry Pi 4 Model B is the latest version of the low-cost Raspberry Pi computer. The Pi isn't like your typical device; in its cheapest form it doesn't have a case, and is simply a credit-card sized electronic board -- of the type you might find inside a PC or laptop, but much smaller.

It costs as little as $35, although you might want to choose the $55 version with its 4GB of RAM for its better all-round performance.

See also: Raspberry Pi: The smart person's guide

WHAT IS THE RASPBERRY PI 4 CAPABLE OF?

The Raspberry Pi 4 can do a surprising amount. Amateur tech enthusiasts use Pi boards as media centers, file servers, retro games consoles, routers, and network-level ad-blockers, for starters. However that is just a taste of what's possible. There are hundreds of projects out there, where people have used the Pi to build tablets, laptops, phones, robots, smart mirrors, to take pictures on the edge of space, to run experiments on the International Space Station -- and that's without mentioning the more wacky creations -- teabag dunker anyone

With the Pi 4 being faster, able to decode 4K video, benefiting from faster storage via USB 3.0, and faster network connections via true Gigabit Ethernet, the door is open to many new uses. It's also the first Pi that supports two screens at one -- up to dual 4K@30 displays -- a boon for creatives who want more desktop space.

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The Raspberry Pi 4 Model B launched on 24th June 2019.

Image: Nick Heath/TechRepublic

HOW DO I GET STARTED WITH THE RASPBERRY PI 4?

One thing to bear in mind is that in its cheapest form, the Pi is just a bare board. You'll also need a power supply, a monitor or TV, leads to connect to the monitor -- typically a micro HDMI cable -- and a mouse and keyboard.

Once you've hooked up all the cables, the easiest way for new users to get up and running on the Pi is to download the NOOBS (New Out-Of-Box Software) installer. After the download finishes, follow the instructions here and it will walk you through how to install an OS on the Pi. The installer allows you to install various operating systems, although a good choice for first time users is the official OS, which is called Raspbian.

The look and feel of Raspbian should be familiar to any recent desktop computer user. The OS, which is constantly being improved, has had several graphical overhauls, most recently to give its interface a minimalistic look, and includes an optimized web browser, an office suite, programming tools, educational games, and other software.

HOW IS THE RASPBERRY PI 4 DIFFERENT FROM ITS PREDECESSORS?

The quad-core Raspberry Pi 4 Model B is both faster and more capable than its predecessor, the Raspberry Pi 3 Model B+. For those interested in benchmarks, the Pi 4's CPU -- the board's main processor -- is offering two to three times the performance of the Pi 3's processor in some benchmarks

Unlike its predecessor, the new board is capable of playing 4K video at 60 frames per second, boosting the Pi's media center credentials. That's not to say, however, that all video will play this smoothly, and supporting this hardware acceleration for H.265-encoded video is currently a work in progress across the Pi's various operating systems, so this is more a potential future feature than something available today.

The Pi 4 also supports wireless internet out of the box, with built-in Wi-Fi and Bluetooth.

The latest board can also boot directly from a USB-attached hard drive or pen drive, and, following a future firmware update, will support booting from a network-attached file system, using PXE. Using a network-attached drive is useful for remotely updating a Pi and for sharing an OS image between machines.

CAN I USE THE RASPBERRY PI 4 AS A DESKTOP PC?

The Pi can be run as a budget desktop, and with the release of the Pi 4 it's never worked better. The biggest benefit for everyday use -- office apps, web browsing, accessing online services -- is the additional memory. 

With 4GB RAM, the Pi 4 no longer struggles with heavy web pages and apps, and is able to switch between full online services such as Google's G Suite and today's JavaScript laden sites without lagging. In many respects, it feels little different to a PC costing many times the price -- thanks to the improved specs and the lightweight yet capable Raspbian desktop.

CAN I WORK ON A RASPBERRY PI 4?

Yes, you can. It's obviously not going to be the same as a high-end laptop, as you're still talking about running a computer on a mobile-targeted processor, but as mentioned the performance is good enough that there's little to complain about. 

With the gradual move from software to online services, the browser is increasingly the only application that a computer needs to run, and on that front the Pi 4 excels, thanks to the extra memory and the Raspberry Pi Foundation's work on optimizing Raspbian's default Chromium browser.

In fact, in the weeks after the Pi 4's release, the areas that are lacking on the Raspbian desktop tend to be related to video playback, although this is due to be addressed by a future software update, and work is continuing on improving 4K playback on media center operating systems such as LibreELEC.

However, the Pi works also well as a thin-client, as I found when I tested its capabilities when running it as a thin client for Windows 10, with performance being almost indistinguishable from running a modern Windows 10 PC, save for the very slow transfer of data to USB sticks. This was based on a Pi 3, so a Pi 4 with its true Gigabit Ethernet should work even better as a thin client.

CAN I BROWSE THE WEB USING THE RASPBERRY PI 4?

Yes, the latest version of the Raspberry Pi's official OS has the Chromium browser, the open-source browser that Chrome is based on. As mentioned, its performance on the 4GB Pi 4 is good, with little lag even on heavy sites, with the only wrinkle being screen tearing on YouTube video at launch, although this is due to be fixed with an update.

CAN I USE THE RASPBERRY PI 4 AS A MEDIA CENTER?

Yes, there are various options if you want to use the Pi 4 as a media center but the most popular choices are the Kodi-based OSes OSMC or LibreElec.

The Pi 4 has the added advantage of a faster and newer CPU and graphics processor, which the Raspberry Pi Foundation has said should be able to play local H.265-encoded video recorded at 3840 x 2160 resolution and 60 frames per second -- although support for this acceleration is still being implemented across the Pi's operating systems. Another advantage is built-in support for Wi-Fi, which makes it easier to stream content to the Pi, while native Bluetooth simplifies the hooking up peripherals.

CAN THE RASPBERRY PI 4 RUN PS1, N64, SNES, NES AND OTHER CLASSIC CONSOLE GAMES?

Yes, a wide range of vintage games will run on the Pi with the help of emulators like RetroPie, including some games from all of the systems listed above, although the more recent the system, the more likely it is that more demanding titles will struggle.

WHICH OPERATING SYSTEMS CAN I RUN ON THE PI?

The Pi can run a large range of systems, including the official Raspbian OS, Ubuntu Mate, Snappy Ubuntu Core, the Kodi-based media centers OSMC and LibreElec, the non-Linux based Risc OS (one for fans of 1990s Acorn computers). It can also run Windows 10 IoT Core, which is very different to the desktop version of Windows, as outlined below.

However, these are just the officially recommended operating systems, and a large array of other OSes also work on the Pi.

CAN THE RASPBERRY PI 4 RUN WINDOWS 10?

Yes, but it's nothing like the full desktop version of Windows 10 that most people are familiar with. Instead the Pi 3 runs Windows 10 IoT Core, a cutdown version of Windows 10 that doesn't boot into the graphical desktop and is designed to be controlled via a command line interface on a remote computer. It can only run a single fullscreen Universal Windows Platform app at a time, for example a kiosk app for a retail store, although other software can run in the background.

However, the Pi can act as a Windows 10 thin client, where Windows 10 is run on a server and streamed to the Pi and, with a powerful enough server, the experience can be virtually identical to running a Windows 10 machine. With the additional power of the Pi 4, and its dual-display support, the Pi's co-creator Eben Upton says he expects the Pi to make further inroads into the thin client market.

Upton says he feels the Pi 4 also likely has the power to run a full desktop version of Windows on Arm, but that any decision to port Windows to the Pi 4 rests with Microsoft.

CAN THE RASPBERRY PI 4 RUN WINDOWS 10 DESKTOP APPS?

The Pi 4 can run Windows desktop apps, although it requires an awful lot of effort to do so, and even then apps will only run poorly.
It used to be possible to do so using the ExaGear Desktop software, although this is no longer on sale. There are free alternatives, however, such as Pi386.

Whichever approach you use, performance will be sub-par, with the tools needed to run Windows apps on the Pi requiring so much processing power that you're basically restricted to running 20-year-old Windows apps and games, and simple modern text editors.
Basically, while it's technically possible, it's not something you'll probably want to do.

CAN THE RASPBERRY PI 4 RUN UBUNTU?

It can run Ubuntu with various desktops, with the Raspberry Pi Foundation highlighting Ubuntu Mate and Ubuntu Snappy Core as standouts.

WHAT ARE THE RASPBERRY PI 4'S SPECS?

  • System-on-a-chip: Broadcom BCM2711   

  • CPU: Quad-core 1.5GHz Arm Cortex-A72 based processor

  • GPU: VideoCore VI

  • Memory: 1/2/4GB LPDDR4 RAM

  • Connectivity: 802.11ac Wi-Fi / Bluetooth 5.0, Gigabit Ethernet

  • Video and sound: 2 x micro-HDMI ports supporting 4K@60Hz displays via HDMI 2.0, MIPI DSI display port, MIPI CSI camera port, 4 pole stereo output and composite video port

  • Ports: 2 x USB 3.0, 2 x USB 2.0

  • Power: 5V/3A via USB-C, 5V via GPIO header

  • Expandability: 40-pin GPIO header

HOW CAN I GET THE MOST FROM MY RASPBERRY PI 4?

It's worth investing in a case to protect the Pi from damage, especially if you're going to be carrying the Pi with you. Note the Pi 4 doesn't fit earlier Pi cases due a change in its layout.

It's also sensible to shell out for a high-speed micro SD card, as outlined below, if performance is important to you.

While the Pi can run many operating systems, if you're after stability and performance then the official Raspbian operating system is a good choice, having been tuned to get the most from the Pi, and thanks to bundling a fast web browser and a decent selection of office and programming software.

One tip if you didn't install the Raspbian OS using the NOOBS installer, and you're running out of space: you can go into the terminal and type 'sudo raspi-config' and then select the option to 'Expand root partition to fill SD card', which will ensure you're using the available space on the card.

HOW CAN I GET HELP WITH THE RASPBERRY PI 4?

With more than 27 million boards sold since the first Pi launched in 2012, the board now boasts a strong community, which helps other users via the official Raspberry Pi site and forums.

HOW DO I KEEP THE RASPBERRY PI 4 UP TO DATE?

If you're running the Pi's official Raspbian operating system then keeping the Pi up to date is relatively straightforward. Just open the terminal and type sudo apt-get update. Once the update is complete, then type sudo apt-get dist-upgrade.

WHAT IS THE POWER CONSUMPTION OF THE RASPBERRY PI 4?

According to tests, the peak power consumption of the Pi 4 is about 7.6W under load and 3.4W when idle.

WHAT RASPBERRY PI 4 KITS ARE AVAILABLE?

There's no shortage of Raspberry Pi kits available, which add everything from speech recognition, to robotic arms to build-it yourself laptops for kids to virtual assistants to the $35 board. Due to the success of the Pi, if you've got an idea for a project, there's probably a kit out there to suit your needs.

WHAT POWER SUPPLY DO I NEED FOR THE RASPBERRY PI 4?

The best choice is the official Raspberry Pi Foundation USB Type-C power supply, which is rated at 5.1V/3A.

WHICH IS THE FASTEST MICRO SD CARD FOR THE RASPBERRY PI 4?

A particularly fast card in a recent round-up was found to be the 32GB Samsung Evo+, which is relatively affordable at less than 10 dollars. 

WHAT SIZE MICRO SD CARD DO I NEED FOR THE RASPBERRY PI 4?

If you're installing the official Raspbian OS you'll need at least an 8GB micro SD card, whereas for the Raspbian Lite you'll need a minimum of 4GB.

CAN I USE WI-FI ON THE RASPBERRY PI 4?

Yes, the board supports 802.11ac Wireless LAN (throughput of around 100 Mbps) and Bluetooth 5.0.

CAN I RUN A NETWORK OF RASPBERRY PI 4S?

Yes, and managing and updating the boards should be made simpler by the ability to boot from a network-attached file system using PXE, allowing admins to share operating system images between machines. PXE support will be added by a future firmware update to the Pi 4.

IS THE RASPBERRY PI 4 64-BIT?

Yes, it's a 64-bit board. However, there are limited benefits to the 64-bit processor, outside of a few more operating systems possibly being able to run on the Pi.

Rather than offering a 64-bit version of the official Raspbian operating system, the Raspberry Pi Foundation has said it wants to focus on optimizing the Pi's official Raspbian OS for 32-bit performance to benefit the millions of older, 32-bit Pi boards that have already been sold.

WHO MAKES THE RASPBERRY PI?

The Raspberry Pi boards are designed by a subsidiary of the Raspberry Pi Foundation, a charitable organization dedicated to advancing computer science education, and manufactured at a Sony factory in South Wales. Since its launch, the Pi has been adopted by many schools, and its availability has also coincided with an almost tripling in the number of people applying to study computer science at Cambridge.

The foundation's founder and board co-creator Eben Upton said he began designing the board as a way to inspire children to learn about computing, after being struck by how few people were applying to study computer science at Cambridge in the mid-2000s.

IS THE RASPBERRY PI JUST A MOTHERBOARD?

Yes, in its cheapest $35 incarnation, although there are a wide range of kits available that bundle together extras like cases, leads and electronics for getting started with hardware hacking -- all for an additional cost, of course. This £70 official Raspberry Pi 4 starter kit bundles much of what you need, including a case, bar the monitor, keyboard and mouse.

HOW DO I KNOW WHICH VERSION OF THE RASPBERRY PI I HAVE?

It's literally written on the top side of the board, for example, 'Raspberry Pi 4 Model B' on a Raspberry Pi 4, typically near the upper edge of the board, just underneath the 40-pin header.

HOW CAN I USE THE RASPBERRY PI 4 TO LEARN PROGRAMMING?

The Pi's official Raspbian OS is loaded with software to teach users about programming, including the drag-and-drop coding tool Scratch, and various utilities for writing and debugging using the Python programming language.

CAN I PROGRAM HARDWARE ON THE RASPBERRY PI?

You can, via the row of 40 GPIO (General Purpose Input Output) pins at the top edge of the board. Hardware such as LEDs, sensors and motors can be hooked to these pins so they can interact with the Pi. Writing simple programs will allow you to send or collect signals using the pins, for example to make an LED flash or to read a measurement from an attached sensor.

CAN THE RASPBERRY PI 4 DO SPEECH RECOGNITION?

Yes, a well-known open-source option is Jasper, which can even be installed on the Pi and used without an internet connection.
Most options for speech recognition rely on a cloud service, hence requiring an internet connection, such as Google Speech or Alexa Voice Service.

An easy way to add speech recognition to the Pi is via Google's Voice AIY (Artificial Intelligence Yourself) kit, which provides all the extra hardware needed to turn the Pi into a Google Voice assistant.

CAN I BUILD A CLUSTER OF RASPBERRY PI 4 BOARDS?

You certainly can, one relatively low-cost options is to combine eight boards together into an OctaPi cluster -- whose combined power is far faster than a single board when calculating prime factors, a key task when cracking encryption.

At the extreme end of the scale is this 750 Pi cluster that has been built at the Los Alamos National Laboratory, and which is due to scale up to 10,000 boards in the future.

HOW DO I BUILD A CLUSTER OF RASPBERRY PI 4S?

There's a tutorial on how to build your own OctaPi, including a step-by-step guide to setting up the software and the hardware.

CAN I TRAIN A NEURAL NETWORK USING THE RASPBERRY PI 4?

No, it's not powerful enough to train neural networks to do anything useful, you're better off using a more powerful computer with a mid to high-end graphics processing unit (GPU) or a dedicated cloud computing instance, such as an AWS P3 or a Google Cloud Platform Cloud TPU (Tensor Processing Unit) instance.

CAN I RUN A NEURAL NETWORK AND DO MACHINE LEARNING ON THE RASPBERRY PI 4?

Yes you can, although you'll likely want to invest in some additional hardware to be effective. For example, Google's Coral USB stick, which accelerates the rate at which the Pi can carry out vision-related tasks, such as facial and object recognition, using its specialized cores. It can accelerate machine-learning models built using Google's TensorFlow Lite library.

WHERE CAN I GET A RASPBERRY PI?

The Raspberry Pi 4 Model B is available now for $35-$55 via official resellers. If you're uncertain what to do with your new Pi you can also buy a full beginner's guide.

IS THERE A RASPBERRY PI 5?

No, and don't expect one for at least a couple of years, based on the time between previous releases of the Pi.

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