Audio stuttering despite low CPU

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Patrick73
Posts: 76
Joined: Thu May 31, 2018 9:39 am

Audio stuttering despite low CPU

Post by Patrick73 » Fri Jun 28, 2019 6:50 am

Hi there,

Last night, for the 1st time, I tried a 5 MHz wide recording using my i7 4700HQ / 8 Mo RAM laptop and had to give up because of horrible stuttering.
The weird thing is that the MAIN panel shows about 35% for Sys and less than 20% for SDR. Thus, I don't understand why this happens ...
I closed all the programs and even with Uno running only, the same occurs.

At 8 MHz BW, "live" listening is also almost impossible though "Sys" and "Sdr" values remain below 40 and 20%.

I checked the "task manager" is everything also looks fine (all below 50%)

Is there something I could do to fix this ?
Thanks a lot.

Patrick

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g1hbe
Posts: 486
Joined: Sat Jan 17, 2015 3:28 pm
Location: Cheshire, UK

Re: Audio stuttering despite low CPU

Post by g1hbe » Fri Jun 28, 2019 7:15 am

Hello Patrick.
That does sound strange. I've never used the recording facility, but with 'live' listening I can go right up to 10 MHz bw without any problems as long as I'm not running anything in the background. My laptop is fairly modest, an i5 at 2.4 GHz with 8 GHz ram.
It's worth checking there isn't some kind of virus scanner churning away deep inside, our new laptop came with all manner of 'run all day' scanners and 'web protection' thingies which I had to hunt down and destroy.
If you don't get anywhere, click on 'support' and open a ticket - the chaps at SDRPlay are very good.

EDIT: Just remembered - there have been several cases of poor quality USB cables causing all manner of glitches at wide b/w. Worth trying a new one if you can.

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Andy

Patrick73
Posts: 76
Joined: Thu May 31, 2018 9:39 am

Re: Audio stuttering despite low CPU

Post by Patrick73 » Fri Jun 28, 2019 7:35 am

Thanks the tips !
There's nothing but Windows Defender installed on this PC and the USB cable is the original one, provided with my RSPduo (I have no other one).

I forgot to mention I'm running the latest SDRuno version.

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Patrick73
Posts: 76
Joined: Thu May 31, 2018 9:39 am

Re: Audio stuttering despite low CPU

Post by Patrick73 » Fri Jun 28, 2019 8:06 am

I just found that the stuttering stops when running the laptop from its PSU ... Bad point : it brings much noise and makes serious DX'ing impossible.
That's why I mostly run this machine on its battery.

Note that the battery is currently fully charged (100%) but this does not prevent the problem from occuring.
No stuttering when recording 1.5 MHz wide. This happens from 4 MHz.

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sdrom33
Posts: 123
Joined: Sun Dec 09, 2018 4:38 pm

Re: Audio stuttering despite low CPU

Post by sdrom33 » Fri Jun 28, 2019 8:46 am

Hi Patrick, some laptops have a battery saving provision that limits the speed (e.g. lower performance) when you are in battery mode. Then your setup works fine at small bandwidth, but when you attempt to increase the speed, the cpu just does not follow. Just check the battery management software. Perhaps you changed a setting there. As for PSU radiation, the best is to place the RSP away from the PC with a long USB buffered cable.I get away with two cables in series with a hub. Another thing I am building now is a shielding box for the PSU.

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Patrick73
Posts: 76
Joined: Thu May 31, 2018 9:39 am

Re: Audio stuttering despite low CPU

Post by Patrick73 » Fri Jun 28, 2019 11:24 am

Thanks for these suggestions.
I just checked the battery management, and it's already set to "high performance".

As for the PSU, it's located as far as possible from the laptop (about 2m) and the RSP is at the other end of the room but maybe the original USB cable is not long enough ...

I'm afraid I can't do any better to solve this problem.

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sdrom33
Posts: 123
Joined: Sun Dec 09, 2018 4:38 pm

Re: Audio stuttering despite low CPU

Post by sdrom33 » Fri Jun 28, 2019 1:32 pm

Patrick, hi again. I would get crazy if I had such a problem! You simply CANNOT have such a problem with an I7 PC!!

Either the PC is faulty (virus maybe?) Or your installed SDRuno is corrupted. I had a similar problem not long ago. First go to the SDRuno folder in Programs & delete the API folder. Then go to ALL PROGRAMS (desktop bottom left) go to Sdrplay folder & delete registry settings. Also uninstall sdrplay_driver. Finally go to the control panel & uninstall what is left. Reboot & do a fresh install: this stuttering must go!

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Mike2459
Posts: 318
Joined: Mon Jul 24, 2017 8:24 pm

Re: Audio stuttering despite low CPU

Post by Mike2459 » Fri Jun 28, 2019 2:34 pm

I just found that the stuttering stops when running the laptop from its PSU ...
This is suggestive of a power management issue. Even though PM is set to high performance there may be some settings that are still causing problems.
You can experiment with these settings, On my laptop there are separate entries for each parameter - One enabled for battery power, the other for line power. You could make the battery settings match the line settings. You can save this as a custom power plan. It will not change the system default power plans but it will give you an additional option. This is on a Win7 32b Dell laptop - Your settings may be different. The downside is that your battery will probably discharge at a faster rate.

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Patrick73
Posts: 76
Joined: Thu May 31, 2018 9:39 am

Re: Audio stuttering despite low CPU

Post by Patrick73 » Mon Jul 01, 2019 12:00 pm

I will have a closer look at it when back home.
For sure, SDRuno is not involved because the stuttering also occurs when playing a clip on YouTube or a MP3 stored on the laptop. Yesterday, as the problem was occurring, I turned off the computer, then turned it back on immediately and everything was fine. Weird :?

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sdrom33
Posts: 123
Joined: Sun Dec 09, 2018 4:38 pm

Re: Audio stuttering despite low CPU

Post by sdrom33 » Wed Jul 03, 2019 12:42 pm

Hi Patrick again. It seldom happens, but it happens that the laptop battery becomes intermittent under certain loads. Then strange things show up, like the pc going suddendly to sleep or the display, yes the display stuttering... This occours in some laptops because the battery is parallel charged, but always taking the brunt of the pc all the same. Swap batteries perhaps?

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