Raspberry pi boards comparison

In a previous post, I explained the most recent model of raspberry pi board, the 3B+ board, and my take on why you want a raspberry pi. This post is about comparing the different models. Again, if you are taking on the raspberry pi hobby, get the 3B+ with quad-core 1.4GHz processor, 1GB memory, and most recent Wi-Fi/Bluetooth on board. It’s easy and fun to use. Other boards are made for specific reasons or tasks.

The following is the most popular one of all, the model 3B+:

Next, let’s see the most recent model, the model 3A+:

If you compare them side by side, you’ll notice that 3A+ is almost the same as the 3A+ except it is missing the stuff on top of the photo:

Here is zero W. It is only about a third of the size of the 3B+ or half the size of the 3A+:

How do these boards compare?

A VS. B VS. Zero

There are three models of raspberry pi boards at the time of this post A, B, and Zero. Please don’t attempt to buy the Compute modules. They are out of the general discussion and only are relevant to circuit designers with enough skill levels to integrate into their products.

Originally there were only two models, the model A, the cheaper with less features and the model B, the full-feature one. There are three generations of them already, gen 1, 2, and 3. Major improvements were made between generations, such as doubling memory and using a quad-core in gen 2 or adding wifi/BT in gen 3. When they make smaller improvements to their designs, such as using a faster processor or better Wi-Fi module, they will put a “+” after the model, such as 3B is superseded by 3B+ with faster processor, faster ethernet, more recent Wi-Fi and Bluetooth connectivity, and more power-hungry than ever.

The model B boards are the main stream boards. The model A boards have less memory, single USB port and no Ethernet, and at times not offered to contrast every model B offering. They have always kept the $35 price tag for B and less for A, such as $20 or $25. The intent of model A is to have it run a project that doesn’t need all the USB ports or Ethernet. Say you want to run some slides on a big screen, you don’t really need more than just the processor and sd card. USB ports or Ethernet are optional. You can save money with model A. Last time I visited Minnesota Institute of Art, I took a peak behind their big screens. They were mostly using model B (probably gen 2 or gen 3, not the plus with metal heat sinks)! I couldn’t take a photo or investigate more though. It’s an art museum any. People go there to see art, not raspberry pi?! Anyway, that would be a use case for model A.

Now (in 2015) the raspberry pi folks wanted to challenge themselves to come up with a computer as cheap as $5 (again accessories count as extra), possibly because many other folks started spinning their own boards with similar specs to raspberry pi and many advertised for low prices. So they did it with model Zero, cramming all that raspberry pi goodness on a board only a third the size of a regular pi. Apparently it is not a prequel to gen 1. They slapped the same processor their gen 1 was using and did away with USB or Ethernet, resulting in a much smaller (only on the look) board that they are selling for $5. Is it really that cheap? I’ll never know. They only sell you limited quantities, such as 1 per customer.

Apparently their successfully answered the challenge to themselves and the community was clamoring about it. They designed a sequel, the Zero-W, with a Wi-Fi/BT on board, same as the Wi-F-/BT on their 3B+, for $10 each. This is better than the Zero, since you can’t really interact with the Zero easily. You first need a mini-HDMI to HDMI adapter to bring out the video. Then you need a USB-otg adapter to hook up a keyboard/mouse combo. If you have the Zero, you have no network! You can install nothing or update nothing. You need to get a USB hub and a USB-Ethernet dongle, for another $10 or more. This newer model is again on limited stock. You can buy more than one if you wish to pay a premium of $15 each, or $20 each if you wish to get more than half a dozen. Definitely these Zero models are NOT for any practical projects that need to be deployed at more than a few locations.

Performance

If you wish to use a raspberry pi as a desktop computer, definitely go with 3B+. 1A and 1B are both obsolete, having single-core sub GHz processors. My oldest raspberry pi is a 1B. It’s painfully slow as a general-purpose computer. I was disappointed at it since the original goal of this device is to teach kids computing. The two mounting holes that were haphazardly placed on the board like an afterthought also bothered me. I did a few projects on it. But nowadays it is sitting idling in its case, inside my box of raspberry pi stuff. In 2014, they cleaned up the board and pushed out 1B+. It’s much easier on the look, and to use, since it comes with 4 USB ports and 4 symmetric mounting holes. This footprint has become the standard for the rest of their models A and B boards. The mounting holes and connectors would be at the same location across multiple generations, and they don’t plan to change. Same processor is used on the model Zero series so far, with a single-core processor now overclocked to 1GHz and 512 MB ram. I do use one of them, the one without Wi-Fi, as a data logger. I had to tether all the wires, USB-otg, to a USB hub, then a USB-Ethernet dongle and a sensor on USB. But since it’s sitting in my garage headless (no keyboard or monitor), I don’t need HDMI or keyboards. I could use the Zero W but still have to have the same stuff due to the sensor on a USB port. Gen 2 only has 2B, no 2A. It’s obsolete as well although you can still buy them. They are better in desktop performance already but would require Wi-Fi dongle to connect to home network. I used to tether my 2B to an Ethernet port on my home Wi-Fi router. Now it’s sitting inside another box with a preloaded program that I might run as a demo. 3B gives you pretty decent desktop performance, comparable to a netbook with Atom processors. I got a retropie running on it, emulating old video game consoles. It has no problem running those emulations. The 3B+ is pretty nice. I use it when I need to get some work done on it. I now have a 3A+, which sports the same processor as the 3B+, with half the memory. It runs fine. I just want one for my small collection and in case I need it for something (probably never, other than blogging about it).

Projects

There are some projects that you need the smaller footprints and you don’t mind soldering/desoldering, you go with ZeroW. Performance is low, as space is premium for your project. You can add more USB ports with custom extension boards but the size and price both go up. You can connect a camera to it too. If you rely on adapter wires to get to the USB port for instance, then your project size will likely double due to the difficulty of bending that adapter to fit in place. Trust me, trying to organize cables with “huge” connectors such as Micro-USB is no fun.

If your project is not limited by size as much, but doesn’t benefit from having more than one USB port, such as a big TV slide show/display case/kiosk, and you potentially want to deploy a number of them, go with model A (3A+). You don’t need the added USB port, Ethernet, or double memory for those tasks.

If you want more flexibility for your project, go with the model B (3B+). You won’t be disappointed. There is a chance you can trim down the requirements into 3A+ in case you deploy your project in many locations.

Note: all photo credits to raspberrypi.org or myself 🙂

2 Responses to Raspberry pi boards comparison

  1. Pingback: Raspberry Pi 3A+ vs. 3B+ and all those other models | Liudr's Blog

  2. Tony says:

    Thank you. I am new to Raspberry Pi. I have a zero w logging temperatures and two 3B+ to play with. Understanding the history and how the different models may be useful is a great help. With the benefit of hindsight and this information, a 3A+ would probably be better for the temperature logging. Looks like I will develop on a 3B+ and migrate it to a 3A+ if that can handle the processing into the future. Thank you for the insights.

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