Nvidia video driver - audio problem

My video card is a Nvidia TNT2 with 32MB, a PIII 733MHz, and Mandrake 9.2.

After installing the Nvidia driver, recording sound with Audacity is distorted (clicks and digital drop outs which sound like echo effects). This happens when there are no other applicactions running. If I disable the Nvidia driver (reverting to nv), the problem goes away.

This happens when using Audacity, but not when using Sweep. Dragging the Audacity window around the screen while recording or playback also creates distortion, but not if I do the same with Sweep or Xmms.

I would not expect recording audio to be a demand on CPU or video resources; am I wrong, or is this a conflict problem?

It sounds ot me like the problem may be a shortage of memory. If the computer has to swap files out onto the hard drive it can slow things down and create bottlenecks. Why don't you try a slimmed down, lightweight desktop/display like Fluxbox when you're using Audacity?

Hi Andrew

I have 256MB of system ram. An alternative desktop is not really a solution - the need to record can be spontaneous.

I feel this is a conflict problem, but I don't know where to look.

Hmmmm

Not much help this time. Is this one too hard, or do I need to re-phrase my problem?

Why does installing the nvidia driver cause problems with sound applications like Audacity?

The Sound Blaster Live! uses Interupt 5, and the Nvidia video driver uses Interupt 11.

The recording software writes to the hard drive in 1MB blocks.

Simply swapping "nv" for "nvidia" in /etc/X11/XF86Config-4 eliminates the cause of the recorded distortion.

The problem would seem to be a memory sharing problem(?). If so, where do I go to check this?