Although the arrival of the Raspberry Pi 3 (RBPi3) heralded a huge speed boost for the Linux hacker board, this $35, wireless-enabled single board computer did not signal a switch over to 64-bit ARM computing. Even though the hardware, following so many other SBCs at the time, was 64 bits, the default Linux distribution from the Raspberry Pi Foundation is still 32-bit.
Eventually, there will be a changeover to 64-bit ARM firmware, as the technology offers significant improvements in performance. More power-efficient chips, such as the 64-bit x86 are also piling on the pressure. However, the Raspberry Pi Foundation is still not committing itself beyond considering a change in the coming months to the 64-bit for the default Raspbian distribution as the reworking of the code required for the changeover is going to be extensive.
The RBPi3 has advanced to the new quad-core of Cortex A53 BCM2837 SoC from Broadcom. Architecturally, this SoC is quite similar to the BCM2836 that the predecessor RBPi2 uses—the quad-core Cortex A7. The Pi Foundation claims that even while operating in 32-bits, the RBPI3 delivers more than 50% better performance than delivered by the RBPi2. This is because of two improvements, one due to the superior architecture of the Cortex A-53, and the other due to the higher clock rate of 1.2 GHz of the RBPi3, as compared to that of 900 MHz of the RBPi2.
While comparing the RBPi3 with the RBPi2, we find the BCM2837 on the RBPi3 is paired with the same VideoCore IV GPU from Broadcom, similar to that in the RBPi2. However, in the RBPi3, the GPU is clocked at a higher rate of 400 MHz. That precludes any video performance at 4K, deep learning projects, or any high-end VR from the RBPi3. On the other hand, the Odroid-C2, being equipped with a Mali-450 GPU, supports 4K video decoding.
Eben Upton, the CEO for the Foundation’s commercial arm, the Raspberry Pi Trading, has explained this. According to Upton, the VideoCore IV 3D is the only 3-D graphics core for the ARM-based SoCs that has been documented publicly and the Foundation wants to make the RBPi more open over time.
Apart from the new SoC, the RBPi3 has also added a wireless chip from Broadcom, the BCM43438, and this enables it with 2.4 GHz, 802.11n Wi-Fi, and Bluetooth 4.1 BLE. With this addition, the RBPi3 steals a march over the Odroid-C2, which lacks wireless, operates on a Cortex-53 Amlogic S905 SoC, and costs $5 more.
Whether to have wireless onboard, or to let users select their own wireless options via Ethernet or USB adapters, has been the subject of an intense debate. As earlier, cost was the main consideration, and the deciding factor came from the dropping prices of wireless chips. Further, the single antenna of the Broadcom chip can be soldered directly onto the board, rather than be used as a module.
Other than the slight shift in the placement of the LED, the new processor, and the wireless capability, the RBPi3 is identical to its predecessor, the RBPi2. They share the same dimensions, amount of RAM, and the 40-pin expansion connector.
