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FIRST LOOK . . . BY TIM BLYTHMAN The new Raspberry Pi 4B R The Raspberry Pi 3B+ was introduced only about one year ago. The Raspberry Pi foundation has clearly been busy in the meantime as they have just announced the release of the Raspberry Pi Model 4B. It’s more than just another upgrade . . . with several delicious new features (as you can see below), it’s a whole new pie! 68 Silicon Chip Australia’s electronics magazine siliconchip.com.au T he Raspberry Pi series of single-board computers (SBCs) has proven immensely popular, with around 20 million sold since the launch of the first model, around seven years ago. We reviewed the most recent model, the 3B+, in our July 2018 issue (siliconchip.com.au/Article/11141). The Pi 4B is similar in many ways to the 3B+, but it is somewhat more powerful. What’s in the Pi? The Raspberry Pi Foundation is touting the Pi 4B as “your new desktop computer”. We’ve tried using some of the older variants as a desktop computer, and while they are usable under light load, they struggle with, for example, large numbers of browser tabs. But the Pi is very powerful compared to most embedded controllers, so in a sense, it bridges the gap between the microcontroller and desktop worlds. The Pi 4B now has options for 1GB, 2GB or 4GB of RAM, which is a considerable step up from the maximum of 1GB in the older version (it wasn’t that long ago that PCs struggled to address 4GB!). The RAM is also more than double the speed now. That alone will make a massive difference in performance, especially for desktop applications. The main SoC (System on a Chip) processor is now an ARM Cortex A72 made with a 28nm process, compared to the 40nm process used for the Cortex A53 in the 3B+. The A53 was a “high-efficiency core” while the A72 is a “high-performance” core. That means it has more cache memory, supports out-of-order execution and has a 15-stage pipeline, compared to the 8-stage pipeline of the A53. The A72 also has a more advanced branch predictor and runs slightly faster, at 1.5GHz rather than 1.4GHz. All these changes mean that you can expect code to run about 60% faster siliconchip.com.au Raspberry Pi 4 specs SoC: Broadcom BCM2711B0 quad-core A72 (ARMv8-A) 64-bit <at> 1.5GHz GPU: Broadcom VideoCore VI Networking: 2.4GHz and 5GHz 802.11b/g/n/ac wireless LAN RAM: 1GB, 2GB, or 4GB LPDDR4 SDRAM Bluetooth: Bluetooth 5.0, Bluetooth Low Energy (BLE) GPIO: 40-pin GPIO header, populated Storage: microSD Ports: 2 × micro-HDMI 2.0, 3.5 mm analog audio/video jack, 2 × USB 2.0, 2 × USB 3.0, Gigabit Ethernet, Camera Serial Interface (CSI), Display Serial Interface (DSI) Dimensions: 88mm × 58mm × 19.5mm, 46 g on the Pi 4B than it did on the Pi 3B+. Communication upgrades The Gigabit Ethernet port is now usable at true Gigabit speeds, as it no longer communicates with the CPU over USB, and two of the externally accessible USB ports are now USB3 types. Dual micro-HDMI sockets replace the single full-size HDMI socket found on the older models. For those folks who like a dual monitor setup, this suddenly got a lot easier with a Raspberry Pi. All these features will certainly make the new Pi 4B more usable as a desktop computer. There are a few other minor changes. It’s powered via a USB-C connector, and the micro-HDMI sockets mean a different cable or adapter is needed. These changes, and the rearrangement of the Ethernet and USB ports, mean that existing cases will not fit the new model. There are also some changes to the way the Pi boots; there is now a boot EEPROM on the board itself which replaces the bootcode.bin file previously stored on the SD card. Support for PXE (network) and USB booting should be available with a future firmware upgrade. The Raspbian operating system has also stepped up, with the most recent Australia’s electronics magazine version (June 2019) changing to Debian’s “Buster” release. We expect that you will need this new version of Raspbian to operate the new version of the Pi. Conclusion It appears that the Pi 4B now has the necessary grunt to truly become a desktop computer and we expect it will be quite popular as new users become more willing to try it out. It’s also likely to be hard to beat in performance/price ratio as an embedded controller. As we are writing this article, only the 1GB variant appears to be in stock (at Core Electronics), although we expect demand to be high. All three models should be available in quantity around the end of September, but you can place a pre-order now (and we recommend that you do so, as they may sell out fast!). The Pi 4B starts at around $56 (not including a power supply, SD card or cables); the 2GB model $72 and the 4GB model $88 (all prices including GST). See the following websites for more details: • www.raspberrypi.org/products/ raspberry-pi-4-model-b/ • https://au.element14.com/ buy-raspberry-pi • https://core-electronics.com.au/ raspberry-pi/boards.html SC August 2019  69