Raspberry Pi 2 review – the Pi you didn’t know you wanted

The Raspberry Pi has been a tremendous success story, ever since the low-cost development board first appeared in 2012. Among enthusiasts and educators it’s sparked an interest in “real” computing, unseen since the halcyon days of the 1980s, and it’s also inspired an army of copycat devices. Now, the Raspberry Pi Foundation is building on that success with the long-awaited successor – the Raspberry Pi 2 Model B.

This isn’t the first time the Raspberry Pi Foundation has updated the Pi. The Model B doubled the RAM from 256MB to 512MB and added a second USB port, and last year the foundation released the B+, which doubled the USB port count to four, plus extra GPIO pins and an improved board layout.

The Raspberry Pi 2, however, represents the first time the company has upgraded the CPU at the heart of the computer. With the switch to a quad-core, 900MHz Broadcom BCM2836 SoC, the new Pi is now multi-core for the very first time. It’s also accompanied by 1GB of RAM – double the provision of the B+ – and the USB ports are now capable of supplying up to 1.2A of current, so you can connect more power-hungry components.

Speaking at the launch of the Raspberry Pi 2, founder Eben Upton said that the biggest challenge in developing the new device had been “hitting the price point”. Yet the Foundation has managed it: although the Pi 2 represents a huge step up in computing power, it still costs only £25. The only disappointment is that the networking port remains staunchly at 10/100 speeds.

On the surface, the new Pi looks like a simple upgrade. It’s much faster, and has more RAM, but visibly nothing changes. The placement of the ports, pins and micro-USB power requirements are all identical, and it’s still powered via micro-USB.

By moving from the 700MHz single-core BCM2835 to the 900MHz quad-core BCM2836, however, the Pi has also moved from the ARMv6 instruction set to the more advanced ARMv7. This means the new board can support not only the Raspbian build of Debian Wheezy, but also Snappy Ubuntu Core and “the full range of ARM GNU/Linux distributions”.

In even bigger news, it’s been promised that the Pi 2 will eventually also support Windows 10. However, Upton has explained that this won’t be a full Windows 10 environment running desktop applications: rather, it will be a command-line environment, aimed at developers designing IoT (Internet of Things) devices.

Despite this dramatic upgrade in capabilities, the Pi 2 remains backwardly compatible with existing hardware and software projects, so for upgraders, the transition will be seamless. Since the physical design is nigh on identical too, most existing third-party cases and add-on boards should also continue to work perfectly with the Pi 2. Close-fitting cases might have a problem, since some of the surface mount components have moved, but for most users all you’ll need to do is re-download Raspbian OS to get the new ARMv7 compatible kernel.

Thanks to its increased clock frequency and over multiple cores, the Raspberry Pi 2 is clearly more powerful than any previous Pi model. Obviously, the effective speed-up will depend on the software you’re running, and whether or not it’s been optimised to run multithreaded, but at the launch, a spokesman demonstrated a Python script that calculated an approximation of Pi then displayed it in visual form in Minecraft. The original Raspberry Pi version took 47 seconds to complete the calculation; using all four cores, the new model completed the job in three seconds.

Even in single-threaded applications, using only a quarter of the Pi 2’s available compute power, you can still see a big difference. We ran SunSpider on a B+ and a Pi 2, and the latter completed the test roughly three times as quickly, with a final time of 4,487ms versus the former’s 14,491ms. Running Google’s Octane browser benchmark brought the B+ to its knees, returning a score of 89.7; on the Pi 2 it gained a score of far better score of 327.

In practice, anyone who uses a Raspberry Pi to develop projects, learn programming, as a basic desktop or media centre will really notice the bump in performance, with general tasks feeling a more responsive within the Raspbian OS. Browsing the web is no longer a chore, and the kid-friendly Scratch programming environment really benefits from the extra zip; you can switch between tabs without having to wait seconds for them to load, and simple jobs such as importing background images complete far quicker. We tried importing a large JPEG on the B+ and the Pi 2 into a Scratch project, and found a huge difference in the amount of time it took to complete the job: on the B+ we had to wait 48 seconds before it appeared in our project; on the Pi 2 that time fell to 20 seconds.

For those who love the Raspberry Pi and all it brings to the table, the Pi 2 is most definitely a good thing. It offers much more power, yet the price remains the same, and the package is completely backwards compatible with the previous model, so upgrading is about as painless as it gets.

Perhaps even more significant, however, is the extra flexibility that the ARMv7 instruction set brings with it. Having the potential to install and run a greater range of operating systems, including (eventually) even a derivative of Windows 10 will only broaden the appeal of the Raspberry Pi, making the company’s target of three million units shipped this year eminently achievable.

Taken from PCPro.

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