In the pursuit of doing crazy things on a Raspberry Pi, my latest endeavor was to see if I could consistently pipe more than a gigabit per second of traffic through WiFi using a Raspberry Pi.
In the past, I had some faltering attempts where sometimes things would work—sort-of—using WiFi 6 (802.11ax, 40 MHz bandwidth, 2x2) using an Intel AX200 M.2 card on the Raspberry Pi Compute Module 4.
For the past year, I've slowly upgraded parts of my network to 10 Gigabit. But 10 Gigabit switches, NICs, and even cabling is a bit more expensive and sometimes annoying to deal with than the very-cheap 1 Gbps equipment most homelabbers are used to.
I dipped my toes into the 2.5 Gbps waters once I got a NAS with 2.5G ports—you can use standard USB NICs that cost less than $50, or PCIe cards for even less. And cabling is easier, since 2.5G works fine over Cat5e (which I already have run to most of my house).
So in order to install a new WiFi 6 Access Point upstairs—and get it's full bandwidth—I upgraded my main 1 Gbps PoE+ switch to a 2.5 Gbps PoE+ switch.
Looking around at options, most switches with more than 4 2.5 Gbps ports with PoE+ seem to cost upwards of $300. And knowing that I'd like to expand my network a bit in the future, I finally splurged a bit and bought this 20-port monstrosity:
Sometimes I like to connect to multiple WiFi networks on my Pi for... reasons.
Other times I like being able to use a better wireless interface than the built-in WiFi module on the Pi 4 or CM4, but don't want to add dtoverlay=disable-wifi in my /boot/config.txt and reboot.
Since Pi OS uses wpa_supplicant, it's actually easy to do this.
First, see what interfaces you have available, e.g. with ip a:
$ ip a
...
3: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
link/ether e4:5f:01:4e:f0:22 brd ff:ff:ff:ff:ff:ff
4: wlan1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
link/ether 84:5c:f3:f6:e9:29 brd ff:ff:ff:ff:ff:ff
If you want to specify a network configuration that only applies to wlan1, create a file named /etc/wpa_supplicant/wpa_supplicant-wlan1.conf, and put your network credentials inside:
I didn't know it at the time, but my results testing the EDUP WiFi 6 card (which uses the Intel AX200 chipset) on the Raspberry Pi in December weren't accurate.
It doesn't get 1.34 gigabits of bandwidth with the Raspberry Pi Compute Module 4 like I stated in my December video, WiFi 6 on the Raspberry Pi CM4 makes it Fly!.
I'm very thorough in my benchmarking, and if there's ever a weird anomaly, I try everything I can to prove or disprove the result before sharing it with anyone.
In this case, since I was chomping at the bit to move on to testing a Rosewill 2.5 gigabit Ethernet card, I didn't spend as much time as I should have re-verifying my results.
January 1, 2021 Update: My 1.34 Gbps benchmark was flawed. See this GitHub issue and this updated blog post to learn more: WiFi 6 is not faster than Ethernet on the Raspberry Pi.
After buying three wireless cards, a new WiFi router, optimizing my process for cross-compiling the Linux kernel for the Raspberry Pi, installing Intel's WiFi firmware, and patching Intel's wireless driver to make it work on the Raspberry Pi, I benchmarked the EDUP Intel AX200 WiFi 6 PCIe card and got 1.34 Gbps of bandwidth between the Raspberry Pi and a new ASUS WiFi 6 router.
This is my story.