performance problems: hiccups with video, audio and graphics

[Avishai <avishai.hendel@gmail.com>]

hello all,

I'm experiencing a rather head-splitting pain with my debian amd64
machine. The symptoms
are not severe, but annoy me to no end: running xscreensaver, or
video, or anything which is a bit heavy on graphics and audio is
always accompanied by 'hiccups' or 'lockups' or 'hangs' or I don't
know how to call them. I mean the graphics just freezes for a fraction
of a
second and then resumes. Also, running xscreensaver with anything but
the simpler programs will always result in a total system hang: the
infamous 'screen frozen, but mouse pointer moves' bug.
Right now I'm runnning the new etch release with a 2.6.18-4-amd64
kernel, but the problems were the same with unstable. I've tried all
possible settings of the AGP rate and driver using the nvidia driver,
and the open-sourced 'nv' driver, nothing seems to matter :(
I'm completely lost here. Really.  :'(
anyone?
thanx,
Avishai.

uname -r: 2.6.18-4-amd64
NVRM version: NVIDIA UNIX x86_64 Kernel Module  1.0-9746
X Window System Version 7.1.1

my current xorg.conf:
# xorg.conf (Xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool,
using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades
*only*
# if it has not been modified since the last upgrade of the xserver-
xorg
# package.
#
# If you have edited this file but would like it to be automatically
updated
# again, run the following commands as root:
#
#   cp /etc/X11/xorg.conf /etc/X11/xorg.conf.custom
#   md5sum /etc/X11/xorg.conf >/var/lib/xfree86/xorg.conf.md5sum
#   dpkg-reconfigure xserver-xorg

Section "Files"
        FontPath        "unix/:7100"                  # local font
server
        # if the local font server has problems, we can fall back on
these
        FontPath        "/usr/share/fonts/X11/misc"
        FontPath        "/usr/lib/X11/fonts/misc"
        FontPath        "/usr/share/fonts/X11/cyrillic"
        FontPath        "/usr/lib/X11/fonts/cyrillic"
        FontPath        "/usr/lib/X11/fonts/100dpi/:unscaled"
        FontPath        "/usr/lib/X11/fonts/75dpi/:unscaled"
        FontPath        "/usr/share/fonts/X11/Type1"
        FontPath        "/usr/lib/X11/fonts/Type1"
        FontPath        "/usr/share/fonts/X11/CID"
        FontPath        "/usr/lib/X11/fonts/CID"
        FontPath        "/usr/share/fonts/X11/100dpi"
        FontPath        "/usr/lib/X11/fonts/100dpi"
        FontPath        "/usr/share/fonts/X11/75dpi"
        FontPath        "/usr/lib/X11/fonts/75dpi"
EndSection

Section "Module"
        Load    "bitmap"
        Load    "dbe"
        Load    "ddc"
        #Load   "dri"
        Load    "extmod"
        Load    "freetype"
        Load    "glx"
        Load    "int10"
        Load    "record"
        Load    "vbe"
EndSection

Section "InputDevice"
        Identifier      "Generic Keyboard"
        Driver          "kbd"
        Option          "CoreKeyboard"
        Option          "XkbRules"    "xorg"
        Option          "XkbModel"    "pc104"
        Option          "XkbLayout"   "us,il"
        Option          "XkbVariant"  "nodeadkeys"
        Option          "XkbOptions"  "grp:switch,grp:shifts_toggle"
        Option          "AddARGBGLXVisuals"   "On"
        Option          "XAANoOffscreenPixmaps" "true"
EndSection

Section "InputDevice"
        Identifier      "Configured Mouse"
        Driver          "mouse"
        Option          "CorePointer"
        Option          "Device"              "/dev/input/mice"
        Option          "Protocol"            "ImPS/2"
        Option          "Emulate3Buttons"     "true"
        Option          "ZAxisMapping"                "4 5"
EndSection

Section "Device"
        Identifier      "NVIDIA Corporation NV34 [GeForce FX 5200]"
        Driver          "nvidia"
        Option          "UseFBDev"            "true"
        Option          "XAANoOffscreenPixmaps" "true"
        Option          "AllowGLXWithComposite" "true"
        Option          "NvAGP"                       "2"
EndSection

Section "Monitor"
        Identifier      "Generic Monitor"
        Option          "DPMS"
        HorizSync       30-65
        VertRefresh     50-75
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Device          "NVIDIA Corporation NV34 [GeForce FX 5200]"
        Monitor         "Generic Monitor"
        DefaultDepth    24
        SubSection "Display"
                Depth           1
                Modes           "1280x1024"
        EndSubSection
        SubSection "Display"
                Depth           4
                Modes           "1280x1024"
        EndSubSection
        SubSection "Display"
                Depth           8
                Modes           "1280x1024"
        EndSubSection
        SubSection "Display"
                Depth           15
                Modes           "1280x1024"
        EndSubSection
        SubSection "Display"
                Depth           16
                Modes           "1280x1024"
        EndSubSection
        SubSection "Display"
                Depth           24
                Modes           "1280x1024"
        EndSubSection
        Option          "AddARGBGLXVisuals" "True"
        DefaultDepth    24
EndSection

Section "ServerLayout"
        Option          "AIGLX"       "true"
        Identifier      "Default Layout"
        Screen          "Default Screen"
        InputDevice     "Generic Keyboard"
        InputDevice     "Configured Mouse"
EndSection

Section "DRI"
        Mode    0666
EndSection

Section "Extensions"
        Option          "Composite" "enable"
EndSection