Pros: The Raspberry Pi can’t be beaten on price, and it offers surprising power for its tiny size and power draw.
Cons: Software for the Pi is still very immature, while other – admittedly more expensive – devices are significantly faster.
More info: Raspberry Pi homepage
Version reviewed: Model B (£29)
Unless you’ve been living under a rock, you’ll have at least heard of the Raspberry Pi. Since the creation of the Raspberry Pi Foundation, a not-for-profit charity created by Eben Upton and David Braben, the credit-card sized computer has rarely spent a day out of the press – despite delays caused by manufacturing issues and unprecedented demand.
The Pi’s problems look to be at an end, and customers are finally receiving their long-awaited boards – but does the device deliver on its promise of affordable, hackable computing in a tiny package?
It’s the size that first grabs you when you handle a retail-model Raspberry Pi. At 85.60mm×53.98mm it’s the approximate size of a credit card, and with a total weight of 45g it’s certainly pocket-friendly. Very few development boards offer the same power in as compact a layout, with the notable exception of the BeagleBone at 86.36×53.34mm.
A compact layout doesn’t mean a lack of features, however. The Model B variant of the Raspberry Pi, as reviewed, boasts HDMI digital video and audio output from a full-size connector, two USB 2.0 ports powered by an internal hub, a 3.5mm jack for analogue audio, an RCA connector for composite video, a 10/100M Ethernet jack and a microUSB socket for the required 5V power input.
Those are just the readily-accessible ports, too: the Pi also features a Display Serial Interconnect (DSI) header for connection to a smartphone- or tablet-style screen, a MIPI camera interface, and a 26-pin general-purpose IO (GPIO) header which offers UART serial, Inter-Integrated Circuit (IｲC) two-wire, Serial Peripheral Interconnect (SPI) and eight addressable general-purpose pins on 2.54mm male headers.
Notable in its absence is an IEEE 1149.1 JTAG connector for debugging. It’s not something that will cause end-users any heartache, but those looking to the Pi as a cheaper alternative to the likes of Qualcomm’s Dragonboard or Samsung’s Origen would do well to consider whether a development system can really live without it.
Another issue prospective buyers will need to consider is the SD card support. With no on-board storage, the Raspberry Pi is reliant on an SD card for its operating system. The faster the card, the better the system performs – but issues with the SoC’s bootloader mean that many Class 10 cards simply don’t work. As a result, users are advised by the Foundation to use a Class 4 or Class 6 card.
When the right SD card is chosen, the Pi is nothing short of a marvel. Booting into a customised build of Debian, compiled for the somewhat outdated ARM11 processor at the heart of the system, is surprisingly quick. Even loading a graphical user interface, via the lightweight LXDE desktop, is pain-free, although scrolling in the included Midori web-browser can be jerky on the more complex pages.
The Pi does show its shortcomings in benchmark tests, however. Running the SysBench CPU benchmark on the Pi results in a 95th percentile request time of 106.72ms, compared to a more reasonable 77.56ms on a Ferroceon 1.2GHz-based DreamPlug (reviewed back in issue 100).
In terms of its price-performance ratio, the Pi is hard to beat – and the sheer power of the Broadcom VideoCore IV GPU makes it a great choice for multimedia tasks, especially where hardware accelerated decoding is supported.
That, sadly, brings us to the final negative of the review: software for the Pi is still at a very early stage, with many features missing compared to rival development boards. Now the systems are finally shipping to customers, however, that will change – and given the popularity of the project, expect to see rapid improvements in the coming months.
It’s easy to mark the Pi down for its lack of JTAG, underwhelming CPU and immature software – but to do so ignores the key advantage the Pi has over its rivals: price. Simply put, there is nothing yet on the market that comes close to offering the Pi’s functionality at the same price point.