Lime SDR Mini sounds problem

Bought a new Lime Mini. The sound is constantly lost for a tenth of a second. The wider the reception band , the more often it disappears. But it disappears even at the 5 MHz band. And on 20 MHz very often. Every 2 seconds. CPU utilization is less than 50%. Updated the firmware. Not help. Airspy Mini does not lose sound on the 6 MHz band. Connected to the USB 3 directly. All tests pass normally. There are no problems at all on the 2.5 MHz band. At 5 MHz, they rarely appear. At 10 MHz or more, the sound is constantly lost.
I tried two computers. Win7 and Win10. Everywhere such a problem.

Video here:

->Start time: Sun May 31 23:22:48 2020

->Device: LimeSDR Mini, media=USB 3, module=FT601, serial=1D5389E523591A, index=0
Serial Number: 1D5389E523591A

[ Clock Network Test ]
->REF clock test
Test results: 42834; 56031; 3692 - PASSED
->VCTCXO test
Results : 6711040 (min); 6711206 (max) - PASSED
->Clock Network Test PASSED

->Read data: 13 07 0C 13 07 0C 02

[ LMS7002M Test ]
->Perform Registers Test
->External Reset line test
Reg 0x20: Write value 0xFFFD, Read value 0xFFFD
Reg 0x20: value after reset 0x0FFFF
->LMS7002M Test PASSED

[ RF Loopback Test ]
->Configure LMS
->Run Tests (TX_2 -> LNA_W):
CH0 (SXR=1000.0MHz, SXT=1005.0MHz): Result:(-14.4 dBFS, 5.00 MHz) - PASSED
->Run Tests (TX_1 -> LNA_H):
CH0 (SXR=2100.0MHz, SXT=2105.0MHz): Result:(-15.3 dBFS, 5.00 MHz) - PASSED
->RF Loopback Test PASSED

=> Board tests PASSED <=

Elapsed time: 3.26 seconds

Does seem like it could be CPU related. Do you have another computer you could try?

The USB speed is constantly changing. Maybe that’s the problem. Top Airspy 6 MHz, bottom Lime

Right, in the video it was showing close to 50% CPU and this seemed high — I get nearer 4-5% on my desktop. 50% doesn’t sound terrible, but no idea how the app behaves at higher CPU utilisation levels.

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I made the band 3 MHz and CPU utilization 15%. The sound is also constantly lost.



I was having similar issues on an i3-6100/z170 and an i7-2675QM. Upgrading to a Ryzen 5 3600 / B450. Remedied my issues. I was having trouble getting more than 6m samples , immediately I was able to crank everything up. My i3-6100 was around 50% utilization as well. Software efficiency I’m sure is a big part too that’s why I’ve stuck to Ubuntu , try a Linux distribution (distro) to see if you get better results too .

I noticed stutters like your video in too. You can also reduce the bandwidth to see if that works. Multi-threaded software is difficult to write. IDK the program you are using (yet).

Take a look at this thread:

My CPU is AMD Ryzen 5 1500X (CPU mark 8,991), Win10 Home 64bit and process 30MHz BW without problem using SDR# (try to find 64bit version - it is much faster!). SDR console use same shark.dll for decimation process (critical process for this type of SDR application) plus CUDA support (optional for Nvidia GPU owner). Simon, author of SDR console, can explained better program critical parts.
For reference above mentioned I3-6100 has 4,182 CPU mark points and i7-2675QM only 3,162!

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