OP25 How many instances of OP25 can be run on an i5?

[maus92]

My experimentation with OP25 / RPi3 / 4 have run its course. I wiped an actual PC (although it's a NUC) and installed Ubuntu 18.04, and OP25 with few issues (although the box used to have another flavor of Linux on it that destroyed itself during an update.) My question is how many instances of OP25 can be run simultaneously assuming there are enough resources? Is there a limitation? Can you assign individual SDR radios to each instance? I'l trying to decide if I want to invest in individual NUCs (or other USFF PCs,) or just build one massive machine...

 

[boatbod]

My experimentation with OP25 / RPi3 / 4 have run its course. I wiped an actual PC (although it's a NUC) and installed Ubuntu 18.04, and OP25 with few issues (although the box used to have another flavor of Linux on it that destroyed itself during an update.) My question is how many instances of OP25 can be run simultaneously assuming there are enough resources? Is there a limitation? Can you assign individual SDR radios to each instance? I'l trying to decide if I want to invest in individual NUCs (or other USFF PCs,) or just build one massive machine...

I'm running 3 instances on an NUC7 i5 and it looks like there is headroom for more.
You may be able to assign specific RTL devices to each instance, but I'd imagine this would require some udev trickery to ensure that the rtl devices always initialize in the same order. I'd imagine this would only be a problem if they have to have band-specific antennas rather than the generic whip that works fine (for me) on 700/800mhz.

RPi4 should be capable of multiple feeds too, but since I've only just taken delivery of my pi4 I haven't had much time to exercise it's limits yet.

 

[maus92]

I'm running 3 instances on an NUC7 i5 and it looks like there is headroom for more.
You may be able to assign specific RTL devices to each instance, but I'd imagine this would require some udev trickery to ensure that the rtl devices always initialize in the same order. I'd imagine this would only be a problem if they have to have band-specific antennas rather than the generic whip that works fine (for me) on 700/800mhz.

RPi4 should be capable of multiple feeds too, but since I've only just taken delivery of my pi4 I haven't had much time to exercise it's limits yet.

(I got sick of all the wires / leads all over my work area, although going headless helped.)

Good to know a NUC can run 3 RTLs (although mine's a 4250U.) I'd start to worry about saturating the USB bus with too many SDRs.

 

[boatbod]

(I got sick of all the wires / leads all over my work area, although going headless helped.)

Good to know a NUC can run 3 RTLs (although mine's a 4250U.) I'd start to worry about saturating the USB bus with too many SDRs.

Haha, I've saturated my "tv room" with too many antennas!

 

[NCAmateurRadioGuy]

@boatbod,
I know this is an old thread but I found a solution a while ago that solves this, you may already know this though.

You may be able to assign specific RTL devices to each instance, but I'd imagine this would require some udev trickery

On the OP25 commands where you use 'rtl=X', you can use the RTL device serial number, given that you make them all different using rtl_eeprom, to uniquely associate a particular OP25 instance with a specific RTL device. For example .rx.py --args 'rtl=00000000'.

 

[a417]

I've run 4+ on an Zotac micro PC (AMD powered NUC, basically). OP25 scales very well for me as you can knock the bandwidth back to 96000 and it keeps the USB happy. Programs that require 2+ Mbps to do the same thing (or streaming I+Q wide open) tend to bottleneck things.
The many year old Zotac I'm using has 4 separate USB busses and I have no issues with 4 or 5 when I'm playing around.

 

[boatbod]

Be careful, I bricked one of my dongles by attempting to change the serial number using the rtl_eeprom tool! Fortunately I was able to copy the config from another (identical) device and recover it, but there were a couple of sweaty minutes when I thought the experience cost me $25!

 

[NCAmateurRadioGuy]

Be careful, I bricked one of my dongles by attempting to change the serial number using the rtl_eeprom tool! Fortunately I was able to copy the config from another (identical) device and recover it, but there were a couple of sweaty minutes when I thought the experience cost me $25!

Luckily, I haven't had an issue with cheap dongles or Nooelec SMArT dongles. Thanks for the heads up!