performance problems with amd64

[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