Not quite sure if this belongs here or in linux part of forum.

It has been said many times that with some models doing cpu intensive things with the computer can cause them to crash. I have noticed recently that sound and video playback has been quite choppy. I have an I3 processor with 4GB of ram. Having tried just about everything else I tried suspending one of the two models and then sound playback was perfect. I know BOINC is supposed to release cycles when other work on the computer demands it but clearly it does not respond quickly enough! Do others have this problem and if so does it only occur on linux?

I must admit when I found the solution I felt a bit stupid for not trying it earlier!

Hi Dave, just to throw out a quick guess--is BOINC running with nice=19?

Is BOINC installed via the distribution? Is it a laptop or desktop?

Installed by extracting tar.gz - 64 bit so I had to install a few libraries to get cpdn to work. As default niceness is 19 for BOINC I assume that is what I am running it as.

I had a sound clipping issue with my previous computer when both cpu and gpu were crunching. (That was AMD Windows.) Pausing gpu crunching solved that problem. Even though Boinc is supposed to behave nicely it doesn�t always seem to do so. With my current computer (Intel Windows) I don�t have any issues with cpu or gpu.

Isn't the default for the GPU only to be active after the owner hasn't used the computer for a few minutes? But of course 'active' means using the keyboard or mouse, so if you're watching a film without compulsively tapping on the keyboard or moving the mouse the GPU must start crunching.

For a film of any length it would be worth suspending the GPU tasks.

If you have the BOINC screensaver activated that can also create problems of interference.

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Cpdn news

Dave - you could try increasing the "latency" for the sound & video cards (lspci -v / setpci ) It won't work for video if you're using the i3's built-in graphics, though.

http://www.mythtv.org/wiki/PCI_Latency

Also you could try changing to a 'lowlatency' kernel, but that will reduce throughput of the models by 5% or so. There's a trade-off between responsiveness and throughput, unfortunately.

... I assume that is what I am running it as.

Open a terminal, type top [enter] and read the "NI" column, [q] to quit. But yes, I believe as long as you're starting via the script it should be 19.

If you're already using Pulseaudio you might want to check if any other applications (like Skype) are configured to use the sound card via Alsa.

Hope you're able to get it working. I can say my AMD laptop and desktop machines with 2.6 kernels and Pulseaudio produce great sound with BOINC tasking all cores. I'll be trying kernels 3.2 and 3.5 soon and I'll report back if anything sounds funny.

Thanks all. I don't use a screensaver - Not even sure it is possible to have the graphics work as a screensaver in linux. I don't do GPU crunching. I will try a bit more playing but if no joy, I will resign myself to suspending one core from crunching while playing youtube or other videos.

Does it only happen with internet content? What about a local video file? How about just an audio file?

Happens with local video, Audio only OK.

Wild guess.
If it's a laptop with no separate display card, it'll be using some of the main memory for display purposes. It'll probably need lots to play videos.
Or at least try to use it.
So it'll be a tug of war between the memory hungry models, and the memory hungry gpu chip.

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Backups: Here

Not a laptop but it is using the built in graphics. Will be interesting to see what difference a discrete card makes when I get one. 4GB is the max my motherboard will accept. Currently I have no restriction on how much memory BOINC can use so that is the obvious next step to play with. If I ever go up to 4 cores or more I think I might just leave one free to see what happens then.

I don't think memory is the problem: I run four CPDN tasks on 4GB without issue (with an integrated GPU). Is this Clarkdale, Sandy, or Ivy? What's the disribution?

Maybe 2D acceleration is the culprit. Try enabling SNA (it'll work on Clarkdale). Here's a couple of links:
https://wiki.archlinux.org/index.php/Intel_Graphics
http://www.webupd8.org/2012/10/how-to-enable-intel-sna-acceleration-in.html

This really shouldn't be happening on modern hardware, but Linux drivers can be tricky to get right.