The Raspberry Pi Foundation has officially launched its latest single-board computer, the Raspberry Pi 2 Model B+ 1G, which boasts an upgraded quad-core processor and double the memory of its predecessors.
It's no secret that the Broadcom BCM2835 system-on-chip processor found in the original Raspberry Pi was outdated, even when the device first launched. It had been designed by Broadcom for use in set-top boxes and other media devices, and while its - closed-source - graphics processor was beefy the single-core 700MHz ARMv6 CPU was slow and lacked compatibility with many operating systems. Since then, numerous models of Raspberry Pi - the Model B Revision 2, Model A, Model B+ and Model A+, not to mention the Compute Module computer-on-module (COM) industrial variant - have launched, but all retaining the outdated and out-classed single-core processor.
The Raspberry Pi 2 is the Foundation's answer to complaints regarding the weedy nature of the original. The BCM2835 has been replaced with a BCM2836, which bumps the stock clock speed to 900MHz and packs four physical processing cores where its predecessor had but one. More importantly, it is also based around the ARMv7 microarchitecture - which means, in theory at least, wider compatibility with mainstream Linux distributions like Canonical's Ubuntu, especially when the more capacious 1GB of RAM is taken into account.
That new microarchitecture could spell trouble for the project as a whole. The good news is that ARMv7 is backwards-compatible with ARMv6: Raspbian, the recommended Linux distribution for the Raspberry Pi, can boot on a Raspberry Pi 2 without modification so long as a new ARMv7 kernel is loaded onto its micro-SD card. Backwards compatibility does not make full use of the benefits of the ARMv7 architecture, however: only applications compiled for ARMv7 will see the full performance of the new chip, and if Raspbian - or any other Pi-oriented distribution - wants to take advantage of that it will mean having to maintain two separate binary distributions, one compiled for ARMv6 and for use with the original Pi and one compiled for ARMv7 and the new Pi 2.
That's not to say that the Pi 2 isn't going to sell like hot-cakes, of course. Thanks to a higher stock clockspeed and four times the processing cores, the chip will outperform its predecessor by anything up to six times even when running ARMv6 applications, and the additional memory is welcomed. Better still, the new model retains the layout of the Model B+ - meaning it's immediately compatible with all the various add-ons and cases designed for its predecessor.
The biggest surprise of the launch comes not from the Foundation, but from Microsoft: the new Raspberry Pi 2 will, the company announced this morning, be able to run a special variant of Windows 10 designed for Internet of Things (IoT) developers. This will be released as a free download for all Raspberry Pi 2 owners, the company confirmed, in a clear move to address the popularity of Linux as a platform for low-cost embedded development and experimentation - especially in education, where the original Raspberry Pi running the Raspbian Linux distribution has proven extremely popular.
The Raspberry Pi 2 Model B+ 1G is available now from the usual retailers, including low-power computing specialist New IT
, priced at the same £30-or-less level as its predecessor - the final selling point that will likely see the new Pi 2 blast past its quad-core rivals in the market.