In case you have missed it – there is a new Raspberry Pi Zero W in town. Since we have a WIFI on board now we should look at the Raspberry Pi Zero W WiFi performance. What should you expect from the tiny board? I’m going to test the chip and see how great it is. And probably answer a question if you can stream from it. If you are interested in how the board stacks against other micro-controllers from the same family, I’ve tested it all for you here.
This is a WIFI module with CYW43438 module (the same found on RPI3) supporting the 802.11n. In theory, the 802.11n technology should give you up to 450Mbps. In practice, the chip has a single band support (20MHz) and the expected speeds are up to *72Mbps.
Mobile readers, check the end of this article for a table
*lab scenario, also thanks to u/Thrawed for the edit.
Raspberry Pi Zero W WIFI performance – testing methodology
The idea is simple. I will walk around with the Raspberry Pi Zero W and iperf server running with it and will report back at various distances. The board is loaded with the latest Raspbian Jessie (full). I’m measuring speed between the raspberry and the PC (windows) hooked by the 1Gb Lan cable. The router used is Linksys WRT1900ACS.
1m
The benchmark default. I’m not expecting any surprises. This is mainly to show you what the board is capable. Here are the results:
Across the floors
Testing distance is about 5m however, the board is on another floor. So there is a ceiling and a wall separating the board from the router. Here are the results:
10m
Let’s see how the range impacts the data transfer. While my router is powerful, the Raspberry Pi Zero W has a tiny space reserved for the antenna. The router has been placed near a window the board was in the visible range of the router. Here are the results:
25m
This is where I’m running out of space. I wanted to avoid breaking the line of sight with the router and this is the furthest I can travel without doing so. Since I was trespassing already, I’m pretty convinced that my neighbor from the other side of the road would be able to access my WIFI with Raspberry Pi Zero W. Here are the results:
| 1m (data) every 2 sec | 1m (speed) every 2 sec | 5m(data) every 2 sec | 5m(speed) every 2 sec | 10m(data) every 2 sec | 10m (speed) every 2 sec | 25m(data) every 2 sec | 25m (speed) every 2 sec | |
| 8.38MBytes | 35.1Mbits/s | 7.38MBytes | 30.9Mbits/s | 4.38MBytes | 18.4Mbits/s | 2.38MBytes | 9.96Mbits/s | |
| 8.50Mbytes | 35.7Mbits/s | 7.25MBytes | 30.4Mbits/s | 3.88MBytes | 16.3Mbits/s | 3.62MBytes | 15.2Mbits/s | |
| 8.25Mbytes | 34.6Mbits/s | 7.12MBytes | 29.9Mbits/s | 3.62MBytes | 15.2Mbits/s | 4.12MBytes | 17.3Mbits/s | |
| 4.75Mbytes | 19.9Mbits/s | 7.00MBytes | 29.4Mbits/s | 3.25MBytes | 13.6Mbits/s | 4.88MBytes | 20.4Mbits/s | |
| 8.12Mbytes | 34.1Mbits/s | 7.50MBytes | 31.5Mbits/s | 4.12MBytes | 17.3Mbits/s | 4.12MBytes | 17.3Mbits/s | |
| TOTAL | 38.0Mbytes | 31.8Mbits/s | 36.2MBytes | 30.3Mbits/s | 19.2MBytes | 16.1Mbits/s | 19.1MBytes | 16.0Mbits/s |
As you can see, Raspberry Pi Zero W is capable of fairly consistent transfers especially when the line of sight is maintained. The terrain obstacles will impact the data transfer for sure, but if you keep the line of sight you should have no issues with the connectivity. To answer the stream question, you probably could. But with the 1GHz clock, save this board for other purposes and buy a Raspberry Pi 3.
