Astropulse causes strange sounds from my monitor


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Questions and Answers : GPU applications : Astropulse causes strange sounds from my monitor

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MonteS
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Message 1489896 - Posted: 16 Mar 2014, 23:28:07 UTC

Whenever an Astropulse Open CL task runs my monitor (ASUS VG248QE LED Display) makes odd repeating sounds remeniscent of the signal discovered in the movie Contact starring Jodie Foster several years ago. The sound is coming from my monitor and not my speakers.
Below is an example task. Each task has its own repeating signal that seems to be unique to that specific task. I have recorded and dated/time stamped a few of them so I could send the sound recording of the task shown below if you are interested. I'm sure you have heard of this before but I was not able to find any information in the forums.

Application: Astropulse v6 6.04 (opencl_nvidia_100)

3/16/2014 5:07:45 PM | SETI@home | Starting task ap_10ap13ab_B5_P1_00273_20140315_11636.wu_0

Boinc is running fine. I am curious as to whether the sound means anything or if it is telling me something is wrong with my monitor. These tasks take about 29 minutes on my system.


Computer configuration:

Power suply : 1500W EVGA Supernova NEX1500
System Board : ASUS Z87 Deluxe
BIOS : BIOS date 10/29/2013 15:03:52 Ver: 16.02
Processor : Intel Quad Core i7-4770K CPU 3.5 GHz (8 CPUs), OC to 4.4 GHz
Ram : 32 Gb DDR3 2400MHz Corsair Dominator Platinum DHX
Operating Sysem : Windws 7 Ultimate 64-bit (6.1, Build 7601)
CPU Cooling : Corsair H100i 240mm Radiator Liquid CPU Cooler

GPU : NVIDIA GeForce GTX 780 on GK110 GPU, 3 GB
Display driver : 335.23

Display BIOS : 80.80.31.00.80

Direct X Version: 11
Display : ASUS VG248QE 24" LED Monitor

Boinc Version : 7.2.39
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Message 1489950 - Posted: 17 Mar 2014, 3:47:18 UTC - in response to Message 1489896.
Last modified: 17 Mar 2014, 3:54:58 UTC

I'm sure you have heard of this before ...

Of course not (I'm reading the forums for years)
Is it April 1-st already? ;)

What is shown on the monitor when you hear "odd repeating sounds"? (screensaver?)
How do you know "The sound is coming from my monitor and not my speakers"? (or fans, DVD, ...)

VG248QE - "Built-in 2W stereo speakers"
https://www.asus.com/Monitors_Projectors/VG248QE/

And no, "sounds" are not by design (SETI@home/AstroPulse applications do not produce any sounds)


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MonteS
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Message 1490414 - Posted: 18 Mar 2014, 1:06:46 UTC

It is obvious from your comments that you think this is somewhat amusing. Actually so do I. However I am serious about my concern that it could be damaging the monitor. I included the reference to the movie Contact, not because I think I am listening to aliens but because the sound coming from my monitor resembles the signals discovered in the movie. I thought a old movie based on SETI research would be a well known reference on this forum.

The sounds are absolutely proven to be associated with the Astropulse V6 6.04 (OpenCL_nvidia_100) tasks because they start when the task starts, stop when it ends, and can be stopped at will by suspending the task. The sounds are not very loud and do not change when adjusting the volume all the way down, all the way up, or muted. The sounds stop if the monitor is turned off. However I did discover tonight that disconnecting the monitor speakers stops the sounds. Could it be that the monitor speakers are picking up some kind of interference signal that is obviously not going through the built in sound card on the system board?

The sounds are not affected by whatever is on the screen. It could be the screen saver as you suggested, but it also could be the Boinc monitor, Microsoft Word or Excel, anything on the internet, an email, etc, etc, etc. I let BOINC run all the time using 2 out of 4 processor cores at 100% while using the computer for whatever. This works well and keeps temperatures very stable.

I thought it was very interesting that each Astropluse Open CL task has its own unique repeating sound. I recorded a few and they are all similar but unique.

I know it is not April fools day but I do appreciate your little bit of humor. I just thought I would share this interesting phenomenon and see if anyone else has had it happen on their system.
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Message 1490601 - Posted: 18 Mar 2014, 11:33:20 UTC

This could be a poorly stabilized power supply chain and some kind of crosstalk from the GPU power supply cables to the audio output cables, e. g. bad shielding. Do you use the audio output from the HDMI port of the graphics card?

I had a similar experience on an older Athlon with the on-board sound. I resolved that issue with a separate audio card.
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Message 1490842 - Posted: 18 Mar 2014, 20:13:01 UTC - in response to Message 1490414.
Last modified: 18 Mar 2014, 20:23:54 UTC

I thought a old movie based on SETI research would be a well known reference on this forum.

Of course I know the movie Contact, I've seen it several times and like it.
But "sound coming from my monitor" 'sounds' more like a ghost movie and not Sci-Fi ;)


However I did discover tonight that disconnecting the monitor speakers stops the sounds.
Could it be that the monitor speakers are picking up some kind of interference signal that is obviously not going through the built in sound card on the system board?

You now know it's not the monitor itself :)

Since "sounds do not change when adjusting the volume all the way down, all the way up, or muted"
the interference is after the digital part and in the analogue amplifier.

Interference may be either electrical (by-wire) or electromagnetic (by-waves)

Computing on GPU do not go 'smooth', it is more like saw motion cutting wood -
RAM/PCIe transfer, memory blocks moved around inside video RAM, prepare some matrix, tell GPU to compute this 'chunk' at once, repeat
(the size of 'chunk' can be adjusted by the user (which will change the sound) but let not do this now)

Data in each task differs.
Many AstroPulse tasks have areas of different size (may be 1% or 10% or 90%) contaminated by earth radio noise.
Those bad parts are artificially filled by random numbers ('white noise' I think).
This is called 'blanking' and is done on the CPU so GPU is in small pauses during this.

Hence the load on the GPU goes like different pulses (on/off) and the electrical current changes.
This causes electromagnetic waves (if not shielded) and also voltage drops/ups on power lines.
These power lines (on the mainboard) also supply the sound amplifier.


So tests:
1) What happens if you connect headphones to the same 'hole' on the back of computer where the speakers were connected?

2) Open the computer and slowly move the power cables inside it (usually there are many) - what happens?

3) Get a piece of Aluminium foil, put it in 2-3 plastic or better paper bags/envelops (for safety, to avoid shorting the components),
put this isolated foil around the video card (front, back).
Do you hear any sound changes?

4) Try if other tests that load the GPU can produce similar effect:
- e.g. the OpenGL / OpenCL 'demos' in the GPU Caps Viewer
http://www.ozone3d.net/gpu_caps_viewer/


I know it is not April fools day but I do appreciate your little bit of humor.
I just thought I would share this interesting phenomenon and see if anyone else has had it happen on their system.

Happened similar to me but long ago (>15 years) - mouse pointer movement on screen was making sound.
I think the cause was the sound wire from CD to sound card was very near along the video card/chip


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Message 1491683 - Posted: 20 Mar 2014, 5:12:13 UTC
Last modified: 20 Mar 2014, 5:15:58 UTC

"So tests:
1) What happens if you connect headphones to the same 'hole' on the back of computer where the speakers were connected?"

I do like your Alf quote.

The past 2 nights I never caught BOINC running an Astropulse Open CL task. Finally tonight it did so I tried a few things.

When the monitor was making its weird noises I rerouted the cable to the monitor speakers to avoid all other cables as much as possible...... No difference.



I plugged headphones into the rear speaker port on the computer, where the monitor speakers were plugged in, ...... No sound from headphones.

I plugged the monitor speakers into what I momentarily thought was audio out on my Bose Companion 2 speakers. I realized it was a 2nd audio input and for the moment it was attached I was hearing the weird sounds in the monitor now amplified quite a bit coming from my Bose speakers. At this time of course the monitor speakers were not attached directly to the computer at all but only to the Bose speakers.

I then attached the monitor speakers to the headphone port on the Bose speakers but about that time the Astropulse task finished so I don't know yet if that will stop the weird sound. I do know that the monitor speakers work because I was able to play music through them. Of course that turned off my Bose speakers and I realized that the small speakers on the monitor were really quite pathetic compared to my Bose speakers. In fact I am now convinced that there is no reason to have them plugged in except to listen to the apparent ghost in the monitor. (obviously referring back to your comment about a ghost movie).

For now I think I will let BOINC keep crunching and take a few days off from this Oddyssey. (And yes that misspelling was intentional.)

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Message 1491799 - Posted: 20 Mar 2014, 11:29:07 UTC - in response to Message 1491683.
Last modified: 20 Mar 2014, 12:18:50 UTC

I plugged the monitor speakers into what I momentarily thought was audio out on my Bose Companion 2 speakers. I realized it was a 2nd audio input and for the moment it was attached I was hearing the weird sounds in the monitor now amplified quite a bit coming from my Bose speakers. At this time of course the monitor speakers were not attached directly to the computer at all but only to the Bose speakers.

So it seems the interference goes through the video cable to the monitor and then somehow through the monitor speakers' cable to the Bose speakers?
Do you use 3-wire mains cables (3-contact plugs) for the computer and monitor (and are they plugged in the same wall outlet)? (I'm not sure I use the correct words)
Maybe monitor have only 2-contact plug by design?


In fact I am now convinced that there is no reason to have them plugged in ...

Yes, if you have so good (and expensive?) Bose speakers there's no point to use those tiny monitor speakers (they are only for office use (to hear simple Windows sounds)).


To get AstroPulse tasks with bigger probability (in case you want "to listen to the apparent ghost in the monitor")
make the SETI@home preferences this way:

SETI@home Enhanced: no
SETI@home v7: no
AstroPulse v6: yes
If no work for selected applications is available, accept work from other applications? yes


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Message 1501564 - Posted: 9 Apr 2014, 3:29:29 UTC - in response to Message 1491799.

So it seems the interference goes through the video cable to the monitor and then somehow through the monitor speakers' cable to the Bose speakers?
Do you use 3-wire mains cables (3-contact plugs) for the computer and monitor (and are they plugged in the same wall outlet)? (I'm not sure I use the correct words)
Maybe monitor have only 2-contact plug by design?


Sorry, I have not been back for several days. I think what you are hinting at is a ground loop which, if I remember correctly, would most likely result from having connected components plugged into different power sources with the grounds at different potentials. All my computer components (computer, monitor, speakers, scanner, printer) get power from the same outlet. All but the printer plug into a UPS (APC Back-UPS XS1500). If it is a ground loop I'll have to really study up on it to figure it out. With what I have tried it seems to be an induced current in the speaker cable (to the monitors built in speakers) originating from the GPU somehow. I will think on that again someday when I have time.

I'll check back once in a while to see if anyone has any comments or similar experience but for now I have disconnected the cable to the monitor's speakers to break the loop if that's what it was.
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Questions and Answers : GPU applications : Astropulse causes strange sounds from my monitor

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