There are a number of different models and versions of the Raspberry Pi computer. But which one is best for your project?
Here's a summary of the main models available:
Photo by Alex Eames of raspi.tv . Used with permission. All Rights Reserved.
Model Specifications Price Pi 3 Model B CPU: 1.2GHz 64-bit quad-core ARMv8 RAM: 1GB USB: 4 ports Connectivity: Ethernet, Wi-Fi, Bluetooth $35 Pi 2 Model B CPU: 900MHz 32-bit quad-core ARMv8* RAM: 1GB USB: 4 ports Connectivity: Ethernet $35 Pi 1 Model B+ CPU: 700MHz 32-bit quad-core ARMv6 RAM: 512MB USB: 4 ports Connectivity: Ethernet $25 Pi 1 Model A+ CPU: 700MHz 32-bit quad-core ARMv6 RAM: 512MB** USB: 1 port Connectivity: None $20 Pi Zero CPU: 1GHz 32-bit quad-core ARMv6 RAM: 512MB USB: 1 micro USB OTG port Connectivity: None $5 Note all Pi models have the same VideoCore IV GPU, an HDMI port, include a 40-pin GPIO header, and feature both a camera interface (CSI) and display interface (DSI). The Pi Zero's HDMI port is mini-HDMI.
* The Pi 2 was recently upgraded from the BCM2836 ARMv7 to the BCM2837 ARMv8 CPU found in Pi 3. It's underclocked at 900MHz and does not include Wi-Fi or Bluetooth.
** The Model A+ was recently upgraded to include 512MB RAM. Its model name and price point remained unchanged.
Raspberry Pi 3
The model with the highest specification is the Raspberry Pi 3 Model B, so for many general purpose projects this is your best bet. It's the most powerful Pi, with the fastest clock speed, the most RAM, and best all-round feature set. If you need speed and power, or your project would benefit from built-in Wi-Fi or Bluetooth, you want the Pi 3. Other models are cheaper, but at $35 it's excellent value for the money.
The Pi 3 is gives a genuinely pleasant desktop PC experience, in no small part thanks to four years of extreme work in optimizing the official Pi operating system, Raspbian. The Pi 3 boots in a matter of seconds, the web browser flies, you can open Minecraft and create a world in no time at all, and intensive applications like LibreOffice and Mathematica respond as they should on a decent PC.
It's also perfect for retro gaming emulation. As Stack Overflow co-founder Jeff Atwood wrote recently , "the ascendance of Raspberry Pi has single-handedly revolutionized the emulation scene. It's fast enough to emulate N64 and PSX and Dreamcast reasonably, all for a whopping $35."
If you ever tried to use OpenCV for computer vision on the Pi 1, you may have had limited success. With the more powerful Pi 3, this is much more feasible.
Pros:Fast, powerful, excellent value for money.
Cons:More power hungry.
Perfect for:Desktop PC, media center, web server, gaming emulator, computer vision.
Raspberry Pi 2
If you own a Pi 2, it's more than likely the original BCM2836-based Model B. Recently, the Pi 2 was upgraded to use the BCM3836 CPU found in the Pi 3. The only real difference between this and the 3B is the lack of Wi-Fi and Bluetooth.
If you have the 2B, you'll find it to be a reasonable desktop PC, though not as powerful as the Pi 3. It handles most things almost as well as a Pi 3 would, and has the same RAM and GPU.
If you owned both a Pi 2 and Pi 3, you could use the 3 for projects that need wireless connectivity and the 2 for ones that don't, and you wouldn't notice much difference between them. The Pi 2 runs on less power than the 3, so that's a bonus if you're not pushing it to its limit.
Gaming emulation, playing video and regular use as a desktop PC would also be appropriate for this model.
Pros:Fast, powerful, good value for money.
Cons:Roughly the same price as superior Pi 3, lacking wireless connectivity.
Perfect for:Desktop PC, media center, web server, gaming emulator.
Raspberry Pi 1 Model B+
Technically speaking, the Model B+ was only a slight improvement on the original Model B, but it added two USB ports and expanded the GPIO header from 26 to 40 pins. It also moved the Pi to a new standard form factor, which it has stuck with for its main models ever since. This format is well-received and ideal for building around. With the B+ came the HAT specification , a standard for add-on boards.
The B+ is perfectly good at most routine tasks, though there's a noticeable sluggishness when using intensive applications like the web browser when compared to the quad-core models. Because every Pi has the same GPU, they all play HD video effortlessly, so using it as a media center is a good option. The only thing you'll notice is the menus won't work quite as smoothly as the Pi 2 or 3.
The B+ gives you a 40-pin GPIO header so you can play with HATs or just access the GPIO pins for electronics projects. You have ethernet and can easily add Wi-Fi and Bluetooth via the four USB ports. Its elegant design dropped some ugly components from the original Pi and neatened up the layout of the board, making it more visually appealing.
The Pi 1 CPU has been used in many millions of units. It's probably the most stable and best supported single-board computer SoC in the world. The B+ has even been certified for space flight–it was used by astronaut Tim Peake on the International Space Station this year as part of the Astro Pi schools' competition, which is expanding into a European-wide competition in 2017.