locked FT8 deep decode speed on Pi 4B #FT8


Bruce KX4AZ
 

I've been trying out WSJT-x with FT8 recently, running the latest full release on a Pi 4B w/4GB memory, 32GB microSD card, and I notice that on a crowded band (e.g. 20m in the afternoon, >35 stations), the final set of deep decodes will roll out as long as five seconds into the next 15s slot.  Is this a typical decode speed for WSJT-x running on a Pi 4B?  .  On my Windows 10 desktop the deep decodes don't spill over more than a second or so.  I'm assuming this just reflects the more limited processing power of the Pi. Not really an issue but I just wanted to confirm my performance is typical.


Mike Phipps <qrz@...>
 

Hi Bruce,

I used to use a Raspberry Pi 4B with 4 GB of memory running the 32-bit version of Raspbian Linux. I even had it running off of a Samsung 850 EVO SSD on a USB 3.0 adapter to cut down on the microSD card loading times. When there are a lot of signals in the band (such as on 20m), it will struggle to keep up, whereas a more powerful desktop or laptop machine on a reasonably modern Intel or AMD processor won’t. I suspect that it is something to do with the way that the ARM processor handles information… it’s a bit different than the x86 processors.

With that said, I have heard that there are some processing speed increases potentially possible when you run a 64-bit operating system on the Pi 4. Raspbian does not currently offer a stable version for arm64/aarch64, but others do (such as Debian, Ubuntu, etc.). You might try swapping out the microSD and trying, say, the arm64 port of Debian Buster (10.x - current stable) or Ubuntu Groovy (20.10 - current stable) on another card to see if you find any speed benefits.

I still have my Pi 4 sitting there doing nothing at the moment, as I have switched over to FreeBSD on an older Dell Latitude laptop for ham activities for now. I could try the arm64 stuff on my Pi 4 at some point, too.

Mike K8WU

On Apr 10, 2021, at 2:40 PM, Bruce KX4AZ <bruce@...> wrote:

I've been trying out WSJT-x with FT8 recently, running the latest full release on a Pi 4B w/4GB memory, 32GB microSD card, and I notice that on a crowded band (e.g. 20m in the afternoon, >35 stations), the final set of deep decodes will roll out as long as five seconds into the next 15s slot. Is this a typical decode speed for WSJT-x running on a Pi 4B? . On my Windows 10 desktop the deep decodes don't spill over more than a second or so. I'm assuming this just reflects the more limited processing power of the Pi. Not really an issue but I just wanted to confirm my performance is typical.


Gary Rogers
 

I had the same problem with my Pi 400. Changing to normal decode helped somewhat but it was still pretty sluggish. I’ve reverted back to my MacBook and all is well now.

On Apr 10, 2021, at 3:21 PM, Mike Phipps <qrz@...> wrote:

Hi Bruce,

I used to use a Raspberry Pi 4B with 4 GB of memory running the 32-bit version of Raspbian Linux. I even had it running off of a Samsung 850 EVO SSD on a USB 3.0 adapter to cut down on the microSD card loading times. When there are a lot of signals in the band (such as on 20m), it will struggle to keep up, whereas a more powerful desktop or laptop machine on a reasonably modern Intel or AMD processor won’t. I suspect that it is something to do with the way that the ARM processor handles information… it’s a bit different than the x86 processors.

With that said, I have heard that there are some processing speed increases potentially possible when you run a 64-bit operating system on the Pi 4. Raspbian does not currently offer a stable version for arm64/aarch64, but others do (such as Debian, Ubuntu, etc.). You might try swapping out the microSD and trying, say, the arm64 port of Debian Buster (10.x - current stable) or Ubuntu Groovy (20.10 - current stable) on another card to see if you find any speed benefits.

I still have my Pi 4 sitting there doing nothing at the moment, as I have switched over to FreeBSD on an older Dell Latitude laptop for ham activities for now. I could try the arm64 stuff on my Pi 4 at some point, too.

Mike K8WU


On Apr 10, 2021, at 2:40 PM, Bruce KX4AZ <bruce@...> wrote:

I've been trying out WSJT-x with FT8 recently, running the latest full release on a Pi 4B w/4GB memory, 32GB microSD card, and I notice that on a crowded band (e.g. 20m in the afternoon, >35 stations), the final set of deep decodes will roll out as long as five seconds into the next 15s slot. Is this a typical decode speed for WSJT-x running on a Pi 4B? . On my Windows 10 desktop the deep decodes don't spill over more than a second or so. I'm assuming this just reflects the more limited processing power of the Pi. Not really an issue but I just wanted to confirm my performance is typical.