Seems that the Raspberry Pi Foundation has risen to the challenge of the flood of “look-alikes” hitting the market. Is the new Raspberry Pi 3 enough to fulfil the needs of Makers that these other boards have been filling up until now? Let's see….
There are a few well needed changes that have been made to the new Raspberry Pi 3. These are changes that push the Raspberry Pi 3 as a good candidate for IoT applications, but there are also issues that havent been addressed.
First the changes:
The new BCM2837 SoC has been used which is the same basic architecture as the old BCM2835 and BCM2836 SoCs, except the 900MHz ARM Cortex-A7 quad core has been replaced with an ARM Cortex-A53 quad core running at 1.2GHz. The Cortex-A53 is a 64bit CPU, which means that you will be able to run either 32bit or 64bit applications. Combining the clock speed increase and a few architectural enhancements made to the CPU core will effectively bring a 50% to 60% increase in performance over the RPi2 for 32 bit applications, or 10x over the RPi1. The 64bit core now brings with it support for Windows IoT, and opens up the flood gate to a much greater choice in software. Initially the Raspberry Pi Foundation will be officially supporting 32bit mode Raspbian, however they have indicated that “We're going to wait until someone can demonstrate a concrete benefit to going to 64-bit before we make that our standard.” This won't stop Makers from creating their own distributions, or if you use Ubuntu/Debian you can already point your repositories to official releases.
The Raspberry Pi 3 also has integrated 802.11n WiFi and Bluetooth 4.1, (BLE) using the BCM43438 chip. This is something that has been really lacking for years and really is imperative if you want to be seen to be “with the times”. Sure, you can always add your own and chew up valuable USB ports and make it a larger footprint. But by providing wireless out of the box they are now aiming squarely at the IoT market. Already there are Makers everywhere dreaming up IoT applications for this board. Time will tell if the BCM43438 will hit the mark for I/O performance.
Update: From the closeup photos so far, it would seem that we are indeed going to be suffering the woes of the LAN9514-JZX USB/ethernet chip on the Rspberry Pi 3.
The graphics processor has been upgraded to the Broadcom VideoCore IV @ 400MHz. This is capable of delivering 1080p @ 60fps using the H.264 codec and new support for the H.265 codec providing a rather limited 1080p @ 30fps.
You can now provide up to 1.2A to the 4 USB ports. This will allow direct connection of 2.5” hard disks, or SSDs without having to use a USB hub to power them. The Raspberry Pi 3 can now draw up to 2.5A which allows much greater expansion options. These major changes have been made just in time. Any longer and the RPi would be left in the back waters. Apart from these changes everything is the same as the RPi2 with; 1G RAM, 100Mbit ether, HDMI, RCA A/V, DSI, microSD and the “industry standard” 40 GPIOs. The form factor is identical except for a few changes to LED positions, however you will need a 2.5A 5V supply to power this. Now the drawbacks: It is surprising that they haven't gone a little further and addressed these issues. Maybe we will see a Raspberry Pi 3+ come out later this year?
Now that we have a 64bit CPU; 1G RAM is really not enough. It limits the real world applications. It's nice that instead of 450MHz RAM we now have doubled to 900MHz - yes, this is essential when using faster processors. It's nice that Low Power DDR2 has been used to reduce power demands. But, it would have been nice to provide at least 2G RAM. It is understandable that space was tight and they had a short time to deliver. This is the problem with defining a form factor. You are stuck with it for the long term. As time goes on we will see the RPi hitting the brick wall with available space and they will have to address it sooner than later.
There's currently no documentation on the architecture and how the USB/ethernet peripherals fit in. The Raspberry Pi 2 suffers from low I/O performance due mainly to the shared USB / ethernet bus. This means that high I/O to ethernet isn't achievable. Likewise USB devices such as hard disks run very slow. From early indications it seems that this has not been addressed and we will still see bad I/O performance. Time will tell.
On the topic of USB. It seems that we are still stuck with USB 2.0 and haven't made the jump to at least USB 3.0. Providing only two USB3.0 ports would have been a lot better than providing 4x USB2.0 ports.
And why are we still using 100Mbit ethernet? A lot of boards are coming out with GbE support, and support for 100Mbit is becoming less and less, especially in datacentres where you generally either disallow it completely, or have to make “special exemptions” on ports.
Are we still stuck with microSD? Why not add in eMMC? Will we still be plagued with the dreaded SD card corruption issues that happen occasionally? Sure we have additional power on the USB ports to support disk or SSD storage, but the less “after market” additions the better and will make it an SBC that supports more of the Maker population “out of the box”. Once again I suspect space is at a premium.
Several changes have been made that makes the Raspberry Pi 3 a good candidate for IoT applications. The addition of inbuilt wireless is important. The CPU core performance increase is good. Certainly Makers will be happy with these items being part of the kit as default. However, the lack of RAM is a major drawback and hopefully we will see a Raspberry Pi 3+ come out later with more than just a piddley 1G. I/O performance is something that is yet to be clarified. It is clear that we only have USB2.0 and 100Mbit ethernet and it looks like we are still stuck with the same USB/ethernet support as exists on the RPi2. Shame.
If you want to get your hands on it; then it is currently on sale now for US$35 from the 29th February.
- ARM Cortex-A53 (quad core) @ 1.2GHz.
- BCM2837 SoC.
- 1GB LPDDR2 RAM.
- Integrated 802.11n WiFi and Bluetooh 4.1, (BLE).
- The usual 100Mbit ether, HDMI, RCA A/V, DSI, microSD & 40 GPIOs.
- Dual core Videocore IV® Multimedia co-processor.
- Of course complete compatibility with RPi1 & RPi2.