# Ham radio listener is split up on old hardware

I'm trying to get a ham radio listener working with RTLSDR on an old Pentium 4. Unfortunately it is playing for a few seconds, then not playing for a split second, very split up. Is there a way I can adjust this line for better throughput? The odd thing is it wasn't showing all memory used or excessive load (1.37)

rtl_fm -M fm -f 440.72M -l 22 | play -r 24k -t raw -e s -b16 -c 1 -V1 -


Is there a minimum requirement for RTLSDR on XUbuntu or is there a better way I need to tune rtl_fm or play - pipe output?

• When you say the load is 1.37, do you mean the load average? It would be more precise to look at the CPU usage percentage (if it's 100% while running this command then you will certainly get audio buffer underruns). – Kevin Reid AG6YO Dec 28 '19 at 20:41
• There's really too much that could go wrong here; the computational load should be very benign, but the Pentium 4-era USB host controllers were terrible, for example. Also, a Pentium 4 computer uses a lot of power, and thus produces a lot of heat, and thus has a large, potentially loud, fan. Might not be the platform of my choice, to be honest. – Marcus Müller Dec 28 '19 at 22:29

The odd thing is it wasn't showing all memory used or excessive load (1.37)

If I remember correctly, the Pentium IV is a single-core architecture with the option for Hyperthreading, which really is just one core with nearly two pipelines.