The Raspberry Pi Foundation has multiplied 3 by 3 and come up with 4: today a new Pi, the Raspberry Pi 4, officially launches with three times the grunt of the previous generation, the Raspberry Pi 3.

The diminutive Raspberry Pi computer has enjoyed a number of updates since the original went on sale in 2012. The $35 Model B machine, which debuted with 256MB RAM and a single 700MHz Arm-compatible CPU core in a Broadcom system-on-chip, has seen RAM and CPU horsepower inch upwards, to the 1GB and 1.4GHz of last year's Raspberry Pi 3 Model B+.

Just over a year after the previous refresh, which didn't merit a number change, comes the Raspberry Pi 4 Model B, rocking changes a-plenty that will both delight and infuriate fans of the credit card-sized kit.

Care for a bit of extra RAM in your Pi?

First the good news. The brains, a Broadcom BCM2711 system-on-chip, features four 64-bit Armv8 Cortex-A72 CPU cores clocked at 1.5GHz, a step up from the A53 found in the Model 3 B+. The Raspberry Pi Foundation reckons its latest shiny-shiny is comparable to an entry-level x86-based system and we’d have to agree. In use, it certainly felt snappier than the last incarnation.

Complementing that CPU bump are some additional RAM options. The claustrophobic 1GB of the 3B+ now enjoys some chunkier siblings in the form of 2 and 4GB LPDDR4 configurations. Sadly, the RAM remains resolutely non-upgradable, though the additional headroom afforded by the extra capacity makes for some intriguing possibilities.

Connectivity has seen improvement with Bluetooth 5 support, and a couple of USB 3 ports, though it is the video modifications that will raise an eyebrow or two.

Seeing double

Gone is the full-sized HDMI type A connector, replaced by a couple of type D micro HDMI connectors. The Pi is now capable of pumping out two 4K outputs to those with the displays to enjoy them (although it will still happily work with the more prosaic gear I had to hand in the office.) Naturally, the silicon is also capable of dealing with H.265 4Kp60 decoding.

While this will be a boon for those seeking dual screen delight, it will also elicit a groan from users wondering where to stick their old larger HDMI connectors after unpacking their shiny new Pi 4.

We asked Pi supremo, Eben Upton, about the thinking behind this, and why the foundation could not have, say, stacked a couple of type A connectors in the same way as the USB sockets are arranged. Upton responded that the challenge was form-factor: "It would have ended up very tall," and that mechanically it would have been a tad "troublesome."

Taking a leaf from the Apple playbook, Upton explained that neither a new cable nor connector adapter would be in the box – both would be cost-extra. Alas, Apple fans would doubtless spontaneously combust upon learning that a 4K compatible cable will go for $5, while a dongle to connect an existing larger HDMI cable to the Pi 4 will retail for $3.

There's good news and bad news on the power front, too. Eagle-eyed readers will have noted a change to USB-C for the power connector, something Upton attributes to a desire to get more power downstream for peripherals plugged into the Pi.

While the Pi team will happily sell customers a USB-C power supply for $8, those wanting to stick with what they have can invest in what Upton called a "shim" for the princely sum of $1 to adapt an older power supply. However, a note of caution must be sounded – while the Pi 4 Model B can get by on 2.5A, downstream peripherals will only be able consume up to 500mA. A full-fat USB-C PSU will make 1.2A available to plugged-in peripherals.

Cases and Cooling

Connector changes aren't the only worries for those looking to upgrade. While the Pi 4 is the same size as its predecessor, you will likely need a new case due to sockets moving about, and we'd also recommend considering a cooling solution.

In our real-world testing – using the machine as our primary computer for a few days – things got quite warm. If you were to load the thing up with serious tasks, then airflow would definitely be a consideration.

Upton warned us that the Pi would start "managing its clocking" – aka dialing clock rates down and performance back a bit to cool down – at around 80°C, adding: "It's definitely a little warmer than the Model 3 B+: idle power is roughly the same, but we can draw about 1W more under full load."

Our Pi 4 Model B, sat on a desk without a case, hit 69 degrees just writing this piece in LibreOffice. Those keen to hammer their Pis, in terms of workload, would therefore be wise to look at options for keeping things cool.

Testing is the hardest word

After the issues with the Power-over-Ethernet HAT, arising from some frankly iffy testing practices, Upton was keen to explain how things had changed with the Pi 4. He told us "the compressed schedule of the PoE HAT was one of the things that caused us to screw up," and so the foundation has seeded the community with test units of the Pi 4 far earlier than usual to iron out any kinks.

The gang took what Upton described as a "bit more of systematic, checklist-orientated" approach, finding and fixing "some pretty scary software issues that looked like hardware issues," prior to launch. Unlike the PoE HAT experience, the crew has been able to deal with problems "not in the glare of public view."

We, on the other hand, love a bit of airing-of-dirty-laundry before all and sundry.

The software

While the Pi 4 remains compatible with hardware add-ons from earlier generations, including the infamous PoE HAT, system software is a different story. The updated architecture naturally requires a some updated drivers for Raspbian, with the refreshed distribution now based on the upcoming Debian Buster, aka Debian 10.

As with previous iterations, you'll need to flash a fresh version of a supported OS to a handy SD card to boot the Pi 4. We tried using previous Arm Linux installations on SD cards lying around the office, and the Pi 4, naturally, would have none of it. So, get a new SD card, install the latest Pi 4-friendly Raspbian on it, or a similar suitable OS, boot it up, and migrate over any documents you need.

Open-source fans will be pleased to hear that the foundation is making progress in whittling down the amount of closed source software it uses. Upton told us that the 3D graphics driver used to power the builtin Broadcom Videocore VI GPU was now fully open source, leaving the camera drivers and legacy codecs still needing work. As for opening up the hardware design itself, Upton did not deem it a priority.

The skin of the Raspbian operating system has also seen some polish, with some of the more garish 3D buttons and frames made flat, as is the fashion du jour.

Of course, it is in the day-to-day usage that the speed increase in the hardware makes itself felt in the software. While one could produce endless charts showing performance differences, things certainly feel considerably snappier in the realms of productivity, web-surfing, and basic code development tasks.

The foundation reckons that the performance boost is anywhere from around 2x to 4x depending on the benchmark you're running, which fits in with our experience. However, we'd have to reiterate that if you run the computer at full steam without some decent cooling, things will quickly slow down as the Pi manages its temperature by down-clocking itself.

Enthusiasts have managed to bring the Arm versions of Windows 10 creaking into life on a Pi. The additional headroom afforded by the extra RAM and the increase in CPU performance could bring Windows 10 on Arm to a wider audience. Having said that, Upton reckoned Microsoft would need to do a bit of work on the drivers first to optimize the operating system for the Pi.

The Specifications

Processor Broadcom BCM2711, quad-core Arm Cortex-A72 (Armv8) 64-bit SoC @ 1.5GHz Memory 1GB, 2GB or 4GB LPDDR4 Connectivity 2.4 GHz and 5.0 GHz IEEE 802.11b/g/n/ac wireless LAN, Bluetooth 5.0, BLE

Gigabit Ethernet

2 × USB 3.0 ports

2 × USB 2.0 ports. GPIO Standard 40-pin GPIO header

(fully backwards-compatible with previous boards) Video & sound 2 × micro HDMI ports (up to 4Kp60 supported)

2-lane MIPI DSI display port

2-lane MIPI CSI camera port

4-pole stereo audio and composite video port Multimedia and graphics H.265 (4Kp60 decode)

H.264 (1080p60 decode, 1080p30 encode)

OpenGL ES 3.0-capable builtin GPU (Videocore VI 3D engine)

The Raspberry Pi 4 Model B hits the channel today in 1, 2 and 4GB RAM varieties, costing $35, $45, and $55 respectively (£33, £44, and £55 inc VAT.) Add $13 for a cable and power supply, and you're looking at an outlay of $68 for the top of the line. Upton reckons that the 2GB version will be the most popular (and the foundation has directed 60 per cent of production capacity into making these particular things) though we'd be tempted to spend a bit more for that extra RAM.

Which brings us on to who is this actually for? In many ways, it seems like a box ticking exercise to meet the demands of enthusiasts while beating off the competition. However, those same enthusiasts may well be left grumpy by the changes to the connectors.

Those new to the Pi will, however, have a much better experience thanks to Linux simply being a bit happier with that critical extra bit of RAM and CPU with which to play.

IoT vendors, on the other hand, will be intrigued by the potential to create ever more intelligent edge devices thanks to the additional power while the dual 4K outputs will have digital signage flingers positively rubbing their hands in glee. ®