Erratic sound channel -

I have an box with XP Pro an abit ic7-max3 MB with a P4 Prescott CPU and a Realteck AC-97 audio, a Gig of RAM, that has an annoying sound problem, but otherwise is solid.

About every 60-70sec when playing sound, doesn't seems to matter the device, be it CD, MP3 from the hard drive, or audio from TV tuner, the sound dies away for about 5 secs. At this point, if the cpu is idling along at say 5%, the cpu usage jumps to about 40%. When the sound comes back, CPU usage falls back to normal. No change in RAM usage throughout this. So we have a cycle of good sound for a minute, volume dropping to near zero for a few seconds, CPU demand rising dramatically, then all returns to normal for the next minute with good sound and so on till the next dip.

I'm not into the nuts and bolts of sound so can someone help and let me know what might be causing this?

Much appreciated for any assistance.

 

Do the CPU usage spikes coincide with the times the volume goes down? If so, look in task manager on the processes tab and see which process it is that's using the CPU at the time. To make it easier, click options and select always on top. Then click twice on the CPU column (click on CPU itself). This will sort them so the processes using the most CPU cycles will be listed at the top. Ingore the system idle process. It will always be around 98 to 99% when nothings happening.

 

Tried to isolate problem by method suggested by Zander. Norton Anti virus, specifically, NAVAPSVC seemed a bit of a hog and then ZONEALARM but dropping both off did not affect bug.

Can only say the rise in CPU usage seems to come immediately after the sound loss. Playing a music CD to test, sound loss occures every 20 secs +/- 1 sec for a period of about 2 secs.

It seems to me a lot like a buffer overrun problem. Is there a sound buffer parameter in XP that can be increased in size?

 

Using Zander's CPU / Tasklist view, do NOT have any audio playing, no media programs loaded. If CPU is ramping up/down we know core problem is not in audio side of system. If CPU ramping ONLY occurs while playing musc, then start in device manager / sound card / hardware acceleration setting / drivers / media program(s) codec conflicts.