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<p class=MsoNormal>I hope this helps…<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>On my WinXP box running on an Intel 2.1Ghz duo core with 3GB
of ram, PowerSDR works fine (read great!) for a “while” then the receive
function gradually starts degrading (drop outs/pops etc) until audio eventually
stops. CPU also rises with the incidence of popping/drop outs. How
long it takes to degrade appears to be related to audio buffer size and sample
rate settings. The higher the sample rate the less amount of time it
takes for performance to degrade. Transmitting also appears to accelerate
the time it takes to degrade. <o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Good performance returns when you restart PowerSDR (first
waiting for the previous instance to unload, which can take a while.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>When running fine (e.g. no drop outs) , the thread that
consumes most of the CPU cycles in the PowerSDR.exe process has this call stack
(or one very similar), at 192K bandwidth.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thread 5-11% cpu<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!NtBuildNumber+0x43<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!MmIsDriverVerifying+0xbb0<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!MmIsDriverVerifying+0x1492<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!PoShutdownBugCheck+0x39e9<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!KeSynchronizeExecution+0x30c<o:p></o:p></p>
<p class=MsoNormal>ntdll.dll!KiFastSystemCallRet<o:p></o:p></p>
<p class=MsoNormal>KERNEL32.dll!WaitForMultipleObjects+0x18<o:p></o:p></p>
<p class=MsoNormal>pthreadVC.dll!pthread_exit+0x111<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Once performance degrades and drop outs begin to occur
frequently. This thread and call stack floats quickly to the top of the sorted
by cpu list. Then stays at the top. This thread jumps to 50%
cpu when you close PowerSDR and stays there for a minute or so. When
it eventually terminates, PowerSDR is unloaded from memory:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thread 34% cpu<o:p></o:p></p>
<p class=MsoNormal>Stack:<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!NtBuildNumber+0x43<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!MmIsDriverVerifying+0xbb0<o:p></o:p></p>
<p class=MsoNormal>hal.dll!HalClearSoftwareInterrupt+0x342<o:p></o:p></p>
<p class=MsoNormal>DttSP.dll!SetKeyerSampleRate+0x27c8<o:p></o:p></p>
<p class=MsoNormal>DttSP.dll!PolyPhaseFIRF+0x28ca<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>When the system has totally degraded this thread stays at
15% cpu <o:p></o:p></p>
<p class=MsoNormal>Thread 15% cpu<o:p></o:p></p>
<p class=MsoNormal>Stack:<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!NtBuildNumber+0x43<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!MmIsDriverVerifying+0xbb0<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!MmIsDriverVerifying+0x1492<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!PoShutdownBugCheck+0x3702<o:p></o:p></p>
<p class=MsoNormal>ntkrnlpa.exe!KeSynchronizeExecution+0x30c<o:p></o:p></p>
<p class=MsoNormal>ntdll.dll!KiFastSystemCallRet<o:p></o:p></p>
<p class=MsoNormal>KERNEL32.dll!WaitForSingleObject+0x12<o:p></o:p></p>
<p class=MsoNormal>libusb0.dll!usb_set_debug+0x266<o:p></o:p></p>
<p class=MsoNormal>libusb0.dll!usb_reap_async+0xf<o:p></o:p></p>
<p class=MsoNormal>libusb0.dll!usb_bulk_write+0x1e<o:p></o:p></p>
<p class=MsoNormal>JanusAudio.dll!OzyBulkWrite+0x21<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
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