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  • Updated 4 years ago
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I have a situation where I can run my Flex-1500 for as much as a day, and then it freezes the waterfall. Sometimes this happens after only a few minutes, but usually, after having cleaned up the system over the past several days, I manage to get at least a few hours of runtime.

Exiting PSDR, then restarting, shows a bizarre solid yellow waterfall pattern. Exiting again, and power-cycling the Flex-1500 fails to restore the FLEX-1500 Software Defined Radio device driver, while the FlexRadio USB Kernel Driver remains intact. And then a few seconds later I get a consistent BSOD claiming the Flex driver had an IRQ less_or_equal -- whatever that means.

So I tried my best to track down the dreaded DPC's, and now I have a bizarre effect of consistently high latencies, measured with DPC Latency Checker, measuring on average, between 1600-1800 usec, peaking at times to around 4 ms. This is with nothing running !!

Now, if that isn't bizarre enough, I can still fire up PSDR and have it piping the I&Q channels at 48 kHz sample rate into VAC. Then when I fire up CWSkimmer feeding off the VAC the DPC latencies magically drop to a pretty consistent 100-200 usec !!!

So, how can running all this interrupt laden stuff actually be improving my system performance? As soon as I quit CWSkimmer the DPC latency shoots consistently skyward again. Could this be related to VAC?

When I run the detailed Latency Checker looking at drivers involved, the NVidia video display driver always tops the list. I have gone through the device manager and disabled just about everything - except - the video driver. Can't very well see what I'm doing if I disable it.

73 de Dave, N7AIG

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Posted 4 years ago

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Photo of K2CM


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Just for grins, reset your database and try again.
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Holy Mackarel! It looks like, unless you are a 14 year old kid really heavy into gaming, the NVidia drivers are a boatload of system poison - on the verge of being malware. I finally bit the bullet and uninstalled the NVidia drivers and now my system sails along at DPC 30-100 usec.
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Jeff Gray

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What are your system specs? How many usb ports? You may need to create an exception in your firewall and antivirus. Also are you running PSDR as administrator. If not you should be. Sometimes depending on your security settings, you may try uninstalling PSDR and re-installing by running the installer as Administrator. Without admin authorization, some needed registry keys may not be or created wrong.
Kill any TSR programs your not needing at the time. Those are the programs that are in the bar next to the clock or are in a window when you click the double arrow next to the clock. TSR programs are programs that are loaded into memory and are idling till called up, so they are using resources that could be used elsewhere. 
  Last make sure your rig is plugged into a usb hub by itself. You will want to find slots in the back mounted directly to the board. The one above it shares the hub. For instance if you lay the motherboard flat facing the usb slots the 2 on left are on same hub and the ones on right are on same hub. Make sure it is plugged into slot closest to board.