OP25 32 bit vs 64 bit OS

[logan437]

Would there be any advantages to using 32 or 64 bit linux OS for OP25. My main consideration is sound quality.
I am building First Responder home monitors using the old Zotac ZBOX-CI320NANO-P and SDR(s) with small antenna. I have the total price down to about $110 (including USB powered speakers). The CPU is the Intel Celeron N2930 so I could use 32 or 64 bit OS. Your advice would be appreciated.

 

[a417]

I have used that exact hardware in both 32 & 64 bit OSs and there is no difference, if your main consideration is sound quality.

 

[boatbod]

I doubt you are going to see any appreciable difference for 32 vs 64bit, but you will notice improvement when running processors that are more powerful than what you might find in an RPi4 for example. I don't know the specs of the Celeron N2930 so I cannot comment directly on that, but I would note that the app (and gnuradio in general) is fairly cpu hungry particularly when you use wider-bandwidth SDR such as Airspy.

@wgbecks ran some benchmarks to compare gnuradio-3.7 vs gnurado-3.8 and it looks like the later versions may have a slight edge, but not enough to be significant.

 

[logan437]

Thanks for the quick reply. CPU utilization and/or memory usage is not a problem on these machines. I can run two steams (using multi) with only about 15% cpu usage and about 250 megs of memory being used for op25. I should have asked for opinions/results on the usage of pulseaudio as well.

 

[boatbod]

Thanks for the quick reply. CPU utilization and/or memory usage is not a problem on these machines. I can run two steams (using multi) with only about 15% cpu usage and about 250 megs of memory being used for op25. I should have asked for opinions/results on the usage of pulseaudio as well.

PulseAudio can sometimes be beneficial and sometimes be a royal PITA. The only way to know for sure is to try it! On my systems I've had a lot of trouble with pulse permissions when running headless, but on desktops with a display manager running and logged in it is usually ok.

That said, you won't be using PulseAudio or ALSA if you are streaming because the data passes from op25 directly to liquidsoap where is is mp3 encoded and streamed to the host server.

 

[a417]

If you're making "an appliance", you should be able to tailor it to hardware at hand..and you wouldn't need pulseaudio at all. I don't use it on that hardware.