I had never known that the sound on P4P800 can drag CPU performance
until I read your post. Mine is a P4P800 Deluxe bought one year ago. I
never bother with the sound since it sounded okay to me. I'll add a PCI
sound card to check it out.
If using the MB soundchip for lighter games/sims, It's not that bad,
but really struggles with newer games, etc.
The main problem I had was with FS-2004 flight sim, which really
pushes the whole computer, because of the heavy graphics and sound.
Disabling the MB soundchip and installing an SB Live helped in the
following ways (with FS2004).
1. Fixed 'crackling' sound-static for aircraft-sounds and ATC/pilot
voices.
Before getting the PCI-card, for some unknown reason, if I changed
graphic resolution (to any other setting, then back again), the
static-pops went away. With the SB-Live I don't have to do this
anymore. It used to be really big headache changing resolutions every
single time.
2. FS2004 ATC voice-chatter, when 'extremely' busy, used to really
ruin frame-rate (down to 1fps! with a 3.3GHz CPU). I think it was
overloading the MB soundchip; It doesn't happen anymore.
3. Aircraft views (panning left, right, back, up) from inside plane,
used to pause the sim for about .75-seconds. Now panning is almost
instantaneous.
4. When ground/aircraft scenery got very complex, every time an
ATC/pilot voice spoke, there was a small and jerky 'stutter'. That's
almost completely eliminated.
The PCI card just sounds better too. Much more bass and treble to
work with too. I found a good prices at pricwatch.com, searching for
'sb live digital'.