It's only been two weeks since the Raspberry Pi Foundation unveiled the Raspberry Pi Compute Module 4 and Compute Module 4 system-on-module products, but it has another trick up its sleeve: The Raspberry Pi 400, the first consumer-centric product in its portfolio — and a throwback to the early days of affordable personal computing, originally floated under the internal name "Project Commodore 64," before "Project Gamma" was picked to make any possible leaks less revealing of the project's intentions.
"It's a nod to a pretty common naming convention, the sort of three digit number that ends in zero," Raspberry Pi Foundation founder Eben Upton tells us in an interview. "Atari, both eight-bit and 16-bit with the 520. Amiga with various hundreds. Acorn with Archimedes 305s, 310s, 440s. It is obviously appealing that if in the far future we do a Raspberry Pi 5, then the Raspberry Pi 5 version will be called Raspberry Pi 500 which I think, personally, is quite nice."
The electronics inside the Raspberry Pi 400, which until you turn to look at the ports at the rear looks like a clone of the existing Raspberry Pi Keyboard, are effectively the same as the ones you'll find powering a Raspberry Pi 4 or the newly-released Compute Module 4. There's a BCM2711 SoC with four Arm Cortex-A72 cores and a VideoCore VI graphics processor, 4GB of LPDDR4 memory — both the minimum and the maximum, with no sign of a 2GB or 8GB model at launch — and a microSD slot for storage.
The board itself is very different, though: Wide and thin, it is spaced out over the majority of the width of the keyboard housing — and on top is a massive sheet of metal attached to the SoC with a thermal pad to act as a passive heatsink, with a pair of vents cut out of the rear plastic housing to provide some airflow.
The heatsink isn't for show: While firmware updates have gradually tamed the Raspberry Pi 4's power draw, it's still a reasonably hungry system — and it's got no less hungry now it is encased in a keyboard. The heatsink, designed by engineer Simon Martin, does more than keep the board from throttling, though: It's allowed the Foundation to boost the clock speed of the BCM2711 from the stock 1.5GHz to 1.8GHz — making the Raspberry Pi 400 faster than the Raspberry Pi 4.
At the rear of the housing are the system's only ports, bar an internal connector for the keyboard: The familiar 40-pin general-purpose input/output (GPIO) header, now upside down and facing away from the user, a microSD slot which comes with a Raspberry Pi OS card pre-installed in the desktop bundle kit, two 4k30 micro HDMI ports, a USB Type-C port for power, two USB 3.0 ports, a single USB 2.0 port — one having gone to the keyboard internally — and a gigabit Ethernet port, plus a Kensington-style locking slot.
The casing is held together without screws, and the whole package feels solid and reassuringly weighty. "I think it's important to make beautiful things," Upton tells us, "and it's just beautiful. It's designed to be an object of desire. The feel of it in your hand, the weight. It just feels like a consumer product, and it's the first time we've ever made anything like that."
Beauty is one thing, but it's nothing without performance. Before getting to the extra 300MHz of stock clock speed — a figure every Raspberry Pi 4 should be able to reach through custom overclocking, using either the fan in the official Power over Ethernet (PoE) HAT or a third-party cooler — there are some key caveats to address.
First, there's no Camera Serial Interface (CSI) or Display Serial Interface (DSI) header to be found — meaning no compatibility with the Raspberry Pi Camera Module range. While the 40-pin GPIO header is present and correct its orientation means HATs are installed upside down and facing away from the user, too, though this can be addressed using a simple 40-pin ribbon cable to move them further down the desk — so long as care is taken the HAT is connected to the end of the cable the right way up, to avoid shorting anything out.
Those aside, and understanding that at launch there's no option for anyone looking for more or less than 4GB of RAM, there's a lot to recommend the Raspberry Pi 400 over a Raspberry Pi 4 for all but embedded and space-constrained uses. At stock speeds, the performance gain is obvious in both synthetic and real-world workloads — anything a Raspberry Pi 4 can run, the Raspberry Pi 400 can run faster.
The thermal performance is outstanding, too. Without a moving part in sight — meaning the system operates entirely silently — the large metal heatsink prevents the Raspberry Pi 400 from throttling even during a 10-minute torture test which sees an uncooled Raspberry Pi 4 in open air dropping its clock speed mere minutes into the run. Although third-party cooling products have proven popular accessories for the Raspberry Pi 4, there'll be no need for them on a Raspberry Pi 400.
Outside of CPU and thermal performance, the Raspberry Pi 400 performs identically to its more compact predecessor: You still get solid gigabit Ethernet throughput, the USB 3.0 ports can still transfer data to an SSD almost as fast as the drive's upper limit, and the performance of the Wi-Fi and Bluetooth radio module is identical — no mean feat, given the chunk of metal covering the antenna.
There's no chance of the iconic and oft-imitated classic Raspberry Pi form factor, with its near-credit-card-size footprint and four mounting holes, is going away — and given the cost difference and its applicability to embedded projects, the Raspberry Pi 4 is likely to remain the best-selling model in the growing family.
There are places where a Raspberry Pi 400 will replace the standard Raspberry Pi 4, though — beginning with the Foundation's charitable efforts. "We've been doing bits of outreach to help kids who've been sent home from school with no computer," Upton explains. "This is a program called Pi Drop, that the Foundation is running."
"It's demonstrated to us complexity and ease of setup is very important to that customer base. And obviously, Raspberry Pi 400 — it sounds trivial, but getting rid of the Raspberry Pi, its case, and the cable between the Pi and the keyboard, it takes three things off the table and it massively reduces the opportunity to misconfigure. So, we'll be rolling over all our charitable work from Raspberry Pi 4 to Pi 400."
"There was also a little bit of a thought about corporate, actually," Upton adds. "We have this great relationship with Citrix around corporate desktop, where you're running a thin client that connects to a Windows instance running on a blade somewhere. There was a feeling that this might be quite a nice form factor for a thin client, that you can put this on a company desktop to run Citrix."
For owners of a Raspberry Pi 4, there's no particular reason — other than it being, as Upton has it, "an object of desire" — to move to the Raspberry Pi 400. It's 300MHz faster, sure, but that same level of overclock and more is easily achievable on any Raspberry Pi 4 — albeit requiring some form of passive or, better yet, active cooling to avoid thermal throttling.
The Raspberry Pi 400 is also entirely ill-suited to embedded work: Even if you shuck it from its housing and discard the keyboard and heatsink, it's considerably larger than any other model of Raspberry Pi going all the way back to the never-publicly-released Alpha boards.
Neither of these are negative points. The Raspberry Pi 400 isn't designed to replace the Raspberry Pi 4 in all use cases, but to make the core technology better suited for particular use cases: Corporate desktops, education, and perhaps even the bedroom programmer — a new generation of hackers typing away on an all-in-one keyboard-computer and inventing the future, just as the generation before them hunched over Commodore 64s, Sinclair ZX Spectrums, Atari 400s and other eight-bit marvels.
The Raspberry Pi 400 is available to order today, priced at $70 system-only and $100 in a new desktop kit bundle that includes pre-loaded Raspberry Pi OS microSD card, mouse, power supply, and Beginner's Guide manual. More information is available on the Raspberry Pi website.