There’s a new Pi in town: the Raspberry Pi 3 Model B+. It’s an upgrade to the previous version 3 Model B. For followers of this little board, its form factor will come as no surprise – it’s the layout that’s remained more or less unchanged for almost four years. However, within this form, there’s some important developments.
The most obvious changes on the new board are the shiny bits of metal hiding a couple of chips. The largest of these covers the System on a Chip (SoC). While this contains the same quad-core processor as on the Pi 3B, there’s a change in the design of the substrate, and more efficient heat dispersal through the heat spreader. These improvements mean it’s now clocked at 1.4 GHz (up from 1.2 GHz on the Pi 3B).
The second big change is also hidden behind metal. The Pi logo conceals a CY43455 chip, which controls the wireless networking. This chip works with both 2.4 GHz and 5 GHz networking (802.11 b/g/n/ac), meaning that the Pi 3B+ can connect to a wider range of WiFi networks than earlier generations, as this allows you to avoid the more congested 2.4 GHz range, giving you the potential for a network speed-up.
The third big change is the introduction of Gigabit Ethernet thanks to a Microchip LAN7515 controller. This is a factor of ten faster than the previous Pi – at least it will be if the rest of your networking infrastructure supports this. Many home routers don’t support speeds faster than 100 Mbps, but in offices and schools you may get a noticeable speed up.
These new specs give a snappier performance to the Pi as a general computer, and the 17% speed-up on the processor may well be enough on its own to convince people using the Pi as a desktop to part with $35 to upgrade. However, we’re more concerned with what the new Pi means to our makes.
The GPIO connection remains unchanged, so as far as physical connections go, there’s no difference, and any wiring you could do on the previous Pi will still work here.
The extra horsepower will come in useful if you need a computationally intensive brain for your make (image processing or artificial intelligence, for example).
WiFi networks run on a ‘channel’ or small range of frequencies within a particular band. Originally, WiFi ran in 14 overlapping 40 MHz channels between 2412 MHz and 2484 MHz. With all the various WiFi networks in the area competing to use this fairly narrow frequency range, there can be quite a lot of interference. In network terms, interference means slow speeds.
Throw in the fact that microwaves and cordless phones also use a similar frequency range and, in a busy area like an office or apartment block, the result can be a dramatic slow down of the network.
The solution to this overcrowding is to open up more frequencies for WiFi networks, and this is where 5 GHz comes in. There’s less demand for frequencies this high, so there are more channels available – 23 non-overlapping channels in fact. This means less overcrowding.
There is a slight complication in that you can’t just double the frequency and expect the properties of the signal to be the same. The biggest difference most people will experience from the different frequencies is that 2.4 GHz is likely to transmit further than 5 GHz. We say likely because there are no hard and fast rules for WiFi range, and it depends on physical objects, atmospheric conditions, and a myriad of other conditions.