Andrew Webb
Jun 24 · 9 min read
Jason Bradbury and Wil Bennett with the brand new Raspberry Pi 4

Raspberry Pi 4 just launched, so should you upgrade from the 3B+? Here’s all you need to know…


Raspberry Pi stunned the computing world when they announced RPi4 in June 2019. Creative design company pi-top have had pre-release models for a while now. So in this first hands-on review, gadget fan Jason Bradbury and pi-top VP of Technology Wil Bennett, put the Raspberry Pi 4 through it paces in a series of tests against the 3B+. Here’s what’s changed… oh and TL;DR you should get one.

As Raspberry Pi inventor and CEO, Eben Upton, said in an exclusive interview on pi-top’s podcast earlier this year, there are two types of RPi upgrades — evolution and revolution.

Originally slated for a 2020 release, Raspberry Pi 4 has arrived a year early and falls distinctly into the revolution category.

What chip is in the Raspberry Pi 4?

The new Pi has a 64-bit Quad-Core ARM Cortex-A72 processor, with a core clock speed of 1.5GHz, similar to the 1.4GHz of the 3B+ (though there’s some rumour the 4’s default clock speed will be increased in the future). The core is still based on ARMv8 technology, like the 3B+, but the new Pi utilises the newer Cortex-A72 microarchitecture that squeezes out a lot more power than the A53 used by its predecessor.

A part of this leap forward in processing power also comes down to a change in the processor’s lithography — the technique used to fabricate individual transistors on the chip. Whereas before a resolution of 40 nanometers (nm) was deployed, the new chip uses much smaller 28nm technology. In practical terms, this means more can be built into a chip of the same size, whilst keeping down overall power draw and waste heat.

Accompanying this boost in processing power is the largest jump in RAM we’ve ever seen from Raspberry Pi. The Pi 4 will be available in 1, 2 and 4GB models, and whereas the 3B+ had 1GB of the older-style LPDDR2, this time it’s been upgraded to LPDDR4.

The performance boost from this change should be very noticeable, as LPDDR4 is theoretically capable of moving data in and out of RAM up to 4 times faster than LPDDR2. In practical terms, this offers a speed boost to all applications, but especially to those that are very memory-intensive, such as image-editing software and web browsers like Chromium.

Raspberry 4 dual micro HDMI

This one’s very exciting — probably the single biggest difference from the previous generations is that there are now two HDMI video outputs. These can be used to drive two screens, extending the total desktop space (as opposed to just mirroring it). Obviously, the applications for this are huge. Each output is capable of comfortably running a single 4K display at 60fps or two 4K displays at 30fps each. The GPU is a Broadcom VideoCore VI, an upgraded version of the VideoCore IV found in the 3B+.

To fit the second display connector onto the board they’ve replaced the single full-sized HDMI port with two micro HDMI ones. This brings Raspberry Pi 4 in line with other Raspberry Pi products such as the Pi Zero and Zero W.

Raspberry Pi 4 is on the left and the 3B+ on the right

Have there been any changes to the USB or ethernet?

Some really big changes, starting with the fact they’ve been swapped around, so the ethernet port is now on the top right (appropriately next to the PoE header, which hasn’t moved) and USB ports on the bottom right (when viewed with the SD card on the left).

As well as two of the usual USB 2.0 ports that we’ve seen on all previous models, the Pi 4 now also has two blazingly-fast USB 3.0 ports, distinguishable by their regulation light blue colour. This is an upgrade that’s long, long overdue, as USB 3.0 has theoretical maximum speeds up to 10 times faster than USB 2.0 and can be found on a lot of competing single board computers (SBCs). It’s worth noting too that with the performance increase USB 3.0 brings, other factors, like the quality and speed of the SD card, will start to more noticeably impact the speed of file transfers, so be sure to buy a good one!

To complement the new faster USB ports, Raspberry Pi have also (finally) switched up to full, real, actual Gigabit ethernet. Members of the community who were excited for the release of the 3B+ model were dismayed to find that, due to the limitations of the internal USB 2.0 bus, that model was only able to produce ethernet speeds of up to 300Mbit/s, less than a third of what Gigabit can achieve.

With these new features under its belt, the Pi 4 can finally pull up a chair at the SBC table and compete with the likes of Odroid, Pine64, Banana Pi, NanoPi (and many more). Until now, devices like these have dominated tasks like network-attached storage (NAS) servers and thin-client applications, but with the upgraded speed and competitive pricing of their newest offering, Raspberry Pi are hoping to grab a bigger slice of the SBC pie that they originally helped create.

What’s changed about powering the board?

Making another significant departure from all previous generations of Pi, the micro USB port has now been replaced with the newer USB-C standard type. And thanks to the switch to smaller processor lithography, all this extra processing power hasn’t come at too much of a cost in electrical power, with the recommended power supply only increasing by half an amp, from 2.5A to 3A. Good news for anyone running the Pi in battery-powered applications.

A surprising easter egg here is that as well as providing power, apparently this USB-C port will support a similar kind of USB OTG ‘gadget’ arrangement offered with the Pi Zero, where it can be plugged directly into a computer’s USB port and can act as an ethernet device, allowing you to view and control the Raspberry Pi via a web browser. We’ve not heard much about this, and given the relatively high current requirements of the 4 combined with the limited current output of typical USB ports, it’s not clear how they plan to pull this off, so we’re excited to hear more about it.

So with a slightly different form factor, will the Pi 4 still work with things built for the Pi 3B+?

Yes, no, and everything in between. The biggest changes in form are the swapping of the USB and ethernet ports, the change from micro USB to USB-C, and the obliteration of full-sized HDMI in favour of two micro ones. But despite these seemingly large changes, a lot else has remained exactly the same. Raspberry Pi have gone to great lengths to keep their signature credit-card dimensions (which are identical to the 3B+), and to ensure that the mounting holes, 3.5mm jack, DSI and CSI connectors, SD card, 40 pin header, PoE header and the LEDs are in the same place as before. Many users speculated that there was going to be a radical form factor overhaul, but for the most part, this isn’t it. But if your case forms a tight fit around the HDMI or USB ports, it won’t work with the new Pi without some, uh, delicate modifications.

What are the other differences between the Raspberry Pi 4 and 3b+?

The GPIO pinout is exactly the same, and backwards compatible, so it’ll still work with the enormous collection of HATs that have been designed for Pis over the years. But that’s not to say there are no upgrades here at all — the engineers have been able to squeeze in a whole lot more I2C, UART and SPI peripherals onto the various pins, about 6 of each now, adding enormous potential to talk to more devices over these protocols. If you’ve ever run into trouble during a project because you wanted, for example, to include more than one device that uses UART, you’re now good for up to six of them.

Wi-Fi and Bluetooth have remained largely unchanged from a hardware point of view, although the Pi 4 does support Bluetooth V5, where the 3B+ was V4.2. So with BT5, expect to see some improvement in Bluetooth range and speed, whilst also using a bit less power.

The operating system has had an upgrade and is now based on the ‘Buster’ Debian release. Older versions of Raspbian won’t work on the new Pi, much like the transition to the 3B+ from the 3B. On the surface, there’s a nice new default background, but otherwise, the basic UI looks largely the same. There’s a nice new tool included for managing how things are arranged when using multiple monitors, a full set of release notes for the new OS can be found here.

At pi-top, we’re looking forward to releasing a new version of pi-topOS Sirius, that builds on the new features Buster brings, and also includes free access to pi-top’s new social making and sharing platform, Further, which will be made available to all Raspberry Pi owners.

One slightly unusual point to mention is that despite the 64-bit processor, the kernel that supports the entire operating system is currently only 32-bit, for now. Raspberry Pi have assured us that this will be updated in future once things have settled down after the launch.

Has anything remained exactly the same?

There have been no changes to the display (DSI) and camera (CSI) connectors, meaning you’ve still the option to connect small screens and the official Raspberry Pi camera. The power over ethernet header and capabilities are unchanged, you can still use PoE with a HAT.

There are some other minor changes to note: there’s a new EEPROM chip on the board that has allowed some configuration a boot files to be moved off of the SD card and onto the RASPI itself. And the video architecture has been respun and is more kernel based allowing for more flexibility in video drivers in future.

And the final thing? The 3.5mm jack, exactly the same, right down to the composite video output, which still clings on even in the age of 4K digital video. Long live CRT televisions!

Should I upgrade to Raspberry Pi 4?

So should you upgrade? Well, of course, you should. Raspberry Pi 4 lets you do so much more — more processing power, more RAM, faster file transfers, and dual monitors to name but a few.

[4]+π4x4GB=awesome

At pi-top, we’re delighted to have Raspberry Pi 4, complete with 4GB of RAM, at the heart of pi-top [4]. And when paired with our Makers Architecture, built in mini screen and battery, it really is a powerful combination that lets you design, code and make anything.

If you’d like to find out more about Raspberry Pi 4 and pi-top [4], visit pi-top.com/kickstarter right now and make sure you’re one of the first to get your hands on it. 🙌

Learning by Making

pi-top brings together a global community of educators, learners, parents, thought leaders, policy makers, activists, developers and other citizens who share a passionate interest and a desire to profoundly improve upon the way we learn, live and work together.

Andrew Webb

Written by

Head of Content for @GetPiTop – education, technology, making. Food lover, terrible astronomer.

Learning by Making

pi-top brings together a global community of educators, learners, parents, thought leaders, policy makers, activists, developers and other citizens who share a passionate interest and a desire to profoundly improve upon the way we learn, live and work together.

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