Thirty years ago, pushing primitive hardware to its limits was what gave birth to the computing industry we know and love today. The makers of the BBC Micro, for instance, spent months rewriting the BASIC interpreter just so that it would squeeze into the available 16KB of ROM.
Since then, developers and users have grown fat on the excess processing power, memory and storage available in today’s PCs, and even the cheapest laptops will cope with several flabbily coded programs simultaneously.
Now, a UK-based charity is attempting to reignite the world’s interest in programming with a computer so stripped to the bone that it uses the equivalent of a 15-year-old processor, contains barely a quarter of the memory of a smartphone, and doesn’t even have a case. And, most thrillingly, it costs a mere $41. It’s called the Raspberry Pi, and we finally have our hands on one for review.
The first thing that shocks you about the Raspberry Pi is how tiny it is: it’s roughly the size of a credit card, with ports and sockets jutting out from every side. The device is so light (45g) that it becomes a hostage to the tension of the cables plugged into it: our chunky HDMI cable lifted the board clean off the desk.
The Raspberry Pi comes in two flavours: the $41 Model B, which we have here, and the lesser-specified Model A, which is due to be released in the coming months. (The Model A and Model B
monikers are a nod to those BBC Micros of 30 years ago, which bore the same names.)
At its heart is a Broadcom BCM2835 system on a chip (SoC) running at 700MHz. This is based on an ARM11 processor, which means the Raspberry Pi won’t run x86 operating systems, be that Windows or even some better known Linux distros, such as Ubuntu. Instead, it operates on specially adapted versions of Debian or Fedora Linux.
If you’re trying to locate the processor on the photo, forget it: it sits beneath the 256MB Hynix memory chip in the middle of the board (see ). Not surprisingly, the combination of a smartphone-class processor and a fairly meagre dollop of RAM doesn’t result in a processing powerhouse. Our Real World Benchmarks don’t run on ARM processors – and even if they did, we’re confident they’d bring the Raspberry Pi to its knees.
The Raspberry Pi Foundation claims “real world performance is something like a 300MHz Pentium II”, and we wouldn’t disagree. The CPU meter in the corner of the Debian screen was frequently maxed out for even the most conservative of applications, such as web browsing. CPU-intensive applications are almost off limits: the GIMP art package took 1min 27secs just to load. In the SysBench CPU benchmark, the Model B took 107ms to complete the purely synthetic prime number calculation test; a mid-range desktop Core 2 Duo E8400 took only 0.85ms.
Such performance benchmarks are missing the point, however: the Raspberry Pi is intended as cheap kit for tinkering – not a desktop replacement. Anyone harbouring thoughts of using one as an inexpensive, general-purpose PC had better think again.
Yet, if the Raspberry Pi lacks general processing grunt, the graphics are a different story. The part of the quote about performance we cruelly lopped off above is “…something like a 300MHz Pentium II, only with much, much swankier graphics”. So while the Raspberry Pi tends to grind to a halt with three or four browser tabs open, the VideoCore IV GPU churned out near-flawless Full HD video in our tests with the Debian distro. It can even play Quake III at a decent 40fps.
The price and caseless design aren’t the only unusual aspects. Another oddity is that the system will boot only from SD cards (see ). A USB hard disk can take over after the initial boot, but that requires jumping through hoops.
External storage can be added via two USB 2 ports (see ), but they’ll normally be occupied by a mouse and keyboard; our system refused to boot until a keyboard was connected. The Raspberry Pi Foundation recommends using a USB hub to add extra ports, but it’s worth noting that the two onboard USB slots are effectively a hub in themselves, sharing a single USB 2 connection and the available bandwidth.
The system is powered by a 5V micro-USB connector (see ). A power supply isn’t provided as standard; you can use a charger from a smartphone or tablet. Users with early units have even reported running the device with four AA batteries, which shows how little damage the Raspberry Pi will do to your electricity bills.
Audio and video are handled by the HDMI out (see ), although there are also composite video and 3.5mm audio outputs for those who want to connect the Raspberry Pi to an older TV, for example (see ). Network connectivity is provided by a 10/100 Ethernet jack (see ) – which is one of the key omissions from the forthcoming Model A – but there’s no onboard wireless chip. You could add one of the few Wi-Fi dongles that work with ARM versions of Linux, but that would again take up a valuable USB slot.
Still, connectivity is better than the size and price would suggest, but a word of caution about accessing it: the exposed ports and pins make it tricky to hold the device firmly while waggling cables in and out – mild force is likely to snap off the USB ports, for example, so handle with care.
Despite its obvious limitations, the Raspberry Pi is nothing short of extraordinary. To create a capable PC for such a price is a magnificent achievement, especially given that many similar projects have failed to reach anywhere near that level of affordability.
We’d certainly want to see the Raspberry Pi enclosed safely in a case before we’d let it anywhere near a classroom of children – more for the protection of the board itself than the children. But for anyone who enjoys tinkering with hardware or wants a mini-testbed to hone their programming skills, it’s a wonderfully ingenuis piece of hardware.
(Additional testing by Gareth Halfacree)