Hi all!
I've been hosting the K3FEF.com websdr since about 2016, and quite frankly I'm just SO done with it.  So Phil has been helping me get things going with Phantom/Nova SDR.  I am NOT a linux guy by any means.  I run a big tech shop but we're all windows with Cisco infrastructure.  I don't think we'd even be allowed to use Linux with what we do.  But that's besides the point.
I have things somewhat running.
I have two machine choices:  An old 2012 Dell Precision 1650 tower w/ 24GB of ram, a 250GB SSD, a Radeon RX580, and an add-on USB3 card that can do 2 amps of juice into the RX888 mkII.  That's what I'm primarily focused on right now. It's running Ubuntu 22 desktop.  Overall it's not bad, but the waterfall seems grainy, and the audio is "skippy" - almost rythmic but in a bad way.

You can listen in on www.k3fef.com:9002.

It took me quite a lot of work to get the RX580 GPU going.  I found that the AMD driver alone did not work.  I had to do the full ROCm install as suggested on the AMD website.  THEN I started to see the GPU get busy (using AMDGPU_top).  So right now, CPU is very low (7-10%), and GPU is running 50-70%.
Per Phil's advice, I added some USB buffer in the rc.local file:
sh -c 'echo 1000 > /sys/module/usbcore/parameters/usbfs_memory_mb'
(That did seem to help a bit).
Overall, the machine doesn't seem to be breaking a sweat - so I'm not sure why it's not running perfect.
Also, when zoomed in the waterfall, can I get some more resolution without killing the system?
Keep in mind, it's an old i7 CPU, but it seems the GPU is doing the bulk of the work anyway right now.

I have another good candidate - also 2012.  It's a Mac Pro 5.1 w/ dual CPU & 12 cores each for a total of 24 cores.  It was my old studio machine.  I have both the factory Radeon card, and another RX580 I could put in there.  The machine is a tank.  It's running linux Mint.  Problem with that is that it doesn't do USB3 so I'm waiting on a PCIe card I can stick in there to test that machine and see how it does (or doesn't LOL).

My biggest PITA, is that whenever I kill RX888_Stream, the desktop just hangs.  The machine is still running and I can get in via SSH, but nothing on the desktop responds.  It's WEIRD!  I have to do a full reboot to get it going again.  That's challenging because I want the system to be stable enough to start back up on it's own (we have a lot of power issues here because I'm in a rural area).

So... I know that's a lot of info, but I'm looking for any feedback, tips, advice, free pizza...etc.

FWIW, I am SO appreciative for the work you guys put into this.  I remember getting my first RX888 years ago and it was sort of disappointing.  I feel like I'm so much further along thanks to the efforts you all have made. :-)

Let me know if any screenshots or info would help - I'm happy to paste whatever might help.
I would also happily pay somebody to remote in tweak as needed.  I've been fortunate to get a lot of nice donations from WebSDR listeners, and it would only make sense to pay-it-forward to provide a "better product". :-)

73!!
Michael - K3FEF

Can you post the TOML you are using? As wrong settings make it work badly too.

Don't you have an more modern Intel CPU gen6 or newer with GPU? As those work very well with OpenCL.

I tried AMD GPU's myself, never got it to work at all.

But it could be wel your Toml settings that are wrong.

Beware the Ubuntu Desktop users the GPU too, it may not like your OpenCL use at the same time.

It's pretty much stock.  I just opened up the bandwidth.  The thing is, I just don't see either the CPU or GPU making much of an effort.  The numbers are low.

[server]
port = 9002
host = "0.0.0.0"
html_root = "frontend/dist/"
otherusers = 1
threads = 1

[websdr]
register_online = false
name = "the NEW K3FEF NovaSDR RX888mk2 in Milford PA USA"
antenna = "ZS6BKW"
grid_locator = "FN21mh"
hostname = "NovaSDR.k3fef.com"
operator = "K3FEF"
email = "K3FEF@ARRL.NET"
callsign_lookup_url = "https://www.qrz.com/db/K3FEF"
chat_enabled = true

[limits]
audio = 100
waterfall = 200
events = 200

[input]
# Core parameters (REAL/direct sampling)
sps = 60000000                # 6 Msps to start; scale carefully
frequency = 0          # Center/base frequency (Hz) for real sampling
signal = "real"              # RX888 MK2 direct sampling (real)

# Performance and quality
fft_size = 131072            # 131072 Reduce if OOM or high CPU (e.g., 65536)
fft_threads = 1
brightness_offset = 0
audio_sps = 20000
waterfall_size = 1024
waterfall_compression = "zstd"
audio_compression = "flac"
accelerator = "opencl"         # Keep "none" on Raspberry Pi; use others only if compiled and supported
smeter_offset = 0

[input.driver]
name = "stdin"
format = "s16"               # rx888_stream outputs s16 (real)

[input.defaults]
frequency = 3875000
modulation = "AM"           # AM | SAM | FM | WBFM | USB | LSB

Any suggestions for a GPU?  I might do some shopping.  :-)

fft_size = 131072 => too small 8388608
audio_sps = 20000 => wrong MUST BE 12000 else FT8 won't work, also 12000 is plenty
waterfall_size = 1024 => 2048 zooms better

You could try putting threads at 2 for fft, but as you use GPU, it may not do anything.

Shopping for a different GPU won't do much, better switch to Intel gen6 (or newer CPU) with build-in GPU.

I use and HP Elitedesk refurbed with 8GB ram....old CPU but more then enough: Intel(R) Core(TM) i5-7500 CPU

The thing is, the internal GPU is very well supported by Intel for GPU use and capable of doing 50MHz bandwidth, we tested. However the USB-bus craps out for 1 receiver

The settings you use are for small bandwitdh, the CPU and GPU will do more with mine.

I have a dell Latitude w/ a 8th gen i5-8265U (w/ Intel UHD graphics 620) and 8GB ram.  Think that might be a good candidate? :-).

Pump the brakes!!  the new settings work great!!  No hiccups in the audio. :-)
Thank you Bas!!!

http://www.k3fef.com:9002/

(My wife has the TV on in the bedroom so lots of RFI hash!)

You're welcome

Quote from: K3FEF on 13 Oct 2025, 15:10 I have a dell Latitude w/ a 8th gen i5-8265U (w/ Intel UHD graphics 620) and 8GB ram.  Think that might be a good candidate? :-).

Normally yes.

Ok - so I got the old Dell running like a champ.  I figured I would push my luck and try to get one of my RX888's (v1) running on the newer Dell Latitude.  In the config, I set it to accelerator = "none" since clinfo doesn't list any devices.
It looks like it's running, but the waterfall is blank and audio is silent.  I see rx888_stream running but not using any CPU at all.  Is the firmware for the RX888 mkII ok to be used on the original RX888?  (BTW, I can feel it getting warm - so it's running!).  lsusb shows it as "Cypress Semiconductor Corp RX888" so it's definitely not in DFU mode.

Edit: I swapped in the RX888 mkII - no change.  So it's not the device.

When you see Cypress Semi Corp RX888 it's running with Firmware loaded.

Looks to me the spectrumserver is failing to start/read samples.

When you set acc to none, it means the CPU has to do all, this will not work at 30MHz...
Upto 10Mhz or so, but forget 30MHz, even a Ryzen can't handle it.

You need OpenCL running.

Ok - so I have to figure out how to run OpenCL on this thing.  It shows the graphics card as a "Intel Corp WhiskeyLake-U GT2 [UHD Graphics 620].  Hopefully I can dig up a driver.

I got OpenCL going and it sees the Intel uhd graphics now! :-)
How do I easily rebuild this install so it sees openCL?
I tried just running install.sh again, but obviously that's not doing it. (my apologies, I'm still learning Linux)

Yeah it does. But the install does a recompile.

It's not always easy. You are not the first that saw this.

Happened to all of us

Else recompile by hand...but enable OpenCL in the toml