First of all, big thanks to @abcd567, @wiedehopf, @TLeconte, and many others who’ve contributed to this hobby of mine.
Your documentation, support, and shared wisdom made this upgrade a lot of fun.
I truly appreciate everything you’ve done to help others!
I’m a sysadmin, so I would say that I have a slight advantage for certain parts…
My Pi 3B+ had been running since 2016 (I think) and I upgraded to the Pi4, 4GB RAM because of a physical location issue.
It’s also hardwired now instead of Wi-Fi.
The rest of the setup is still the same. I moved each RTL dongle over to the new Pi, migrated the service then disabled the service on the old Pi3.
I was able to migrate 1090 graphs/rrdtool and it’s fun to see the difference. -Screenshot below.
I also switched to READSB, can anyone explain why I see:
An increase in messages, aicraft seen, ADS-B range?
A decrease in ADS-B tracks seen?
I’m happy to share more details about my setup if anyone is interested.
From the Misc chart. Seems you were running with gain set to the max, and now it’s on auto. At max you were probably overloading the SDR and loosing signal. So now it’s at a more suitable level your stats are up. Not sure why tracks would be down though.
It looks as if it is the reduction in tracks with a single position.
In the older portion of the graphs the dongle looks like it was overloaded and creating data errors that appeared as false tracks with a single position. The later portion with auto gain does not have as many errors, hence the reduced number of tracks.
Makes sense. And looking again now at the chart on a larger screen (was on my phone this morning) it seems that the tracks with more then one position (the green part) is in fact higher now then it was before the change. So, though it looks “less” it’s probably in fact seeing “more”.
I was actually looking at that the other day and used Copilot/ChatGPT to get some info by uploading my Graphs1090 stats. I also ran different gain settings for a few days instead of the auto gain and found my sweet spot.
Edit: The Pi4 is still on Wi-Fi. Will be moved to ethernet one day…
From Copilot:
Pi 3B+ Time Range
From: ~July 1 To: ~September 28
This covers the entire summer period up until the day you physically replaced the Pi 3B+ with the Pi 4.
Pi 4 Time Range
From: ~September 29 To: present (December in your graphs)
Everything after the hardware swap is Pi 4 data — including the smoother message‑rate curves, higher MLAT counts, and lower CPU load.
Message Rate (avg daily)
Pi 3B+: ~1.5–1.8 million
Pi 4: ~1.8–2.1 million
Change: Higher sustained peaks, fewer bottlenecks
2. Aircraft Seen (daily)
Pi 3B+: 1,200–1,400
Pi 4: 1,400–1,600
Change: More consistent, fewer decoding stalls
3. MLAT Aircraft
Pi 3B+: 150–250
Pi 4: 250–400
Change: Major improvement due to better CPU timing
4. Maximum Range
Pi 3B+: ~250–270 NM
Pi 4: ~250–270 NM
Change: No difference (range is antenna‑limited)
5. Median Signal Level
Pi 3B+: Stable
Pi 4: Stable
Change: No RF change expected
6. CPU Utilization
Pi 3B+: 60–70% under load
Pi 4: 25–35% under load
Change: Much more headroom, smoother decoding
7. Temperature
Pi 3B+: 55–60°C
Pi 4: 60–65°C
Change: Slightly warmer but normal
8. System Stability
Pi 3B+: Occasional USB bottlenecks, decoding stalls
Pi 4: No bottlenecks, stable even with multiple SDRs
Change: Significant improvement
Summary
The Pi 3B+ sometimes showed higher raw counts, but this was partly due to duplicate or partial decodes when the CPU was overloaded.
The Pi 4 produces cleaner, more accurate data with better MLAT performance and smoother message throughput.
RF range did not change — that’s determined by antenna, LNA, and geography.
The Pi 4 ensures you decode everything you physically receive without choking.
Thanks for the great write-up, love hearing about your experiences with the various hardware. It’s been a couple/few years since I had my node online, but we recently moved to a new town and now that I’m starting to feel “settled" I want to dig out my other (newer) RPi4 and start collecting flight data again.
I’ve got a basic RTL-SDR radio, may eventually need to invest in a better antenna: https://www.rtl-sdr.com/
What’s the best approach these days, follow official Flight Aware documentation for self-hosted or PiAware on GitHub? Any general pro-tips you could share that might help a neophyte trying to ease back into things? Better (or different) hardware to consider? I’ll invest some time reading and researching and get my stuff back online, at which point I hope to be in a better position to fully appreciate the detail you’ve included. Happy New Year!
Some stats didn’t make sense so I went over graphs1090 again and unfortunately it looks like Copilot/chatgpt was wrong. I asked it a few times in different ways and it ended up at the same conclusion…
”If your Pi3B+ was active during the earlier, more stable portion of this timeline (especially pre-mid-2025), then yes—your setup may have been better dialed in. The Pi4 offers more power, but unless you re-optimized everything (PPM, gain, antenna, service configs), it might not have translated into better performance.”
On my initial query I did not focus on long term data and it shows in the attached screenshot.
I’m going to go over wiring and basics but it looks like the initial move to a pi4 was good until/around October 20th(ish).
Copilot/Chatgpt did help to dial in the gain and other settings that I didn’t know about but my situation has not improved as much as my previous post says. Sorry about that.
@peatrick If you’re starting from scratch, the standard FlightAware image is great. If you know how to install an OS on a raspberry pi, the FA install is also pretty easy.
Thank you kindly for the great advice, sir – unfortunately, the most recent backup i could locate was from 2020, so probably makes sense for me to start fresh. My site has been up and feeding various sites (FA, ADSBExchange, FR24 & RadarBox) for just one or two short weeks now, but i have much reading and research to perform, as i continue to tinker in the background in hopes of improving coverage.
Baby steps, i guess… before blowing it all away and starting fresh (again), i want to ensure i’ve got a solid foundation to work from moving forward. Appreciate you sharing your recent experience, while on a similar journey. I also started with an RPi 3B+ before turning that into a Pi-hole appliance and upgrading to the 4B (4GB). Not sure the 5 series makes much sense, at that point i’d start looking for used x86 / mini PCs.
Very happy to give some input back to the community!
For me the most important ‘backups’ were the feeder sharing keys, site names etc.
I regretted wiping the pi a few times when I lost those. The rest can be easily reinstalled.
At the moment it looks like a pi zero 2W might perform similarly to the pi4 so I would personally forget about trying anything on a 5 or a PC. I wanted to move multiple feeders (AIS, ADS-B, ACARS, and ATC) and dongles to a single Pi4 but it looks like it might actually be a worse setup!
My 2 cents: I don’t know about your SDR dongle, but be aware that the zero 2W may not going to run all the dongles. I gave it a quick try. Couldn’t get an airspy mini to work. Like i said, i just gave it a quick try and didn’t bother afterwards due to having a Pi 5 around.
Thanks! I moved Ais-catcher off of the Pi 3B+ to a Pi zero 2W. It looks like it’s performing the same as before.
Bottom line, I tried migrating everything that was running on the Pi 3B+ to a Zero 2W and a Pi4 and things haven’t improved. I tried to fix something that was working…
The Pi4 running readsb/FA is connected to the official FlightAware (blue) dongle. It has been running for many years, maybe I should try a different USB SDR.
AIS-Catcher on the Pi Zero 2W is using a recent Nooelec V5
