Forum Linux.debian/ubuntu DUal Screen et Accélération graphique

Bonjour à tous, je vous expose le probleme :
Je suis sous débian Sarge, j'ai fais basculer apt en unstable, le kernel est 2.6.14 (recompilé pour les drivers nvidia).
J'ai 2 écrans , 2 cartes graphiques NVIDIA et un Xorg.conf me faisant fonctionner le tout en dual sans problèmes. Or l'accélération matérielle ne fonctionne plus.

Avant (avec un écran et une GEFORCE FX5200 j'avai un scrore satisfaisant de plus de 1000fps sur glxgear et dorénavant je plafone a 350...

Ce qui me dégoute c'est que mes 2 cartes sont des Nvidia, que le driver est correctement installé avec un "Direct rendering = yes". J'ai même le splash screen nvidia sur les 2 écrans au boot du serveur X. L'accélération matérielle est donc gérée logiciellemnt mais quelque chose à l'ai de la freiner, est ce le Xinérama ???

Avant d'avoir le 2ème écran, j'avait fais un dual avec un crt et une vieille carte cirrus 1 mo et l'accélération matérielle était gérée. Je ne pense donc pas au'il y ait incompatibilité entre dual-screen et 3D ...

Je poste plus bas mon xorg.con car je voi vraiment pas d'ou peut venir le problème, merci.

# 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/lib/X11/fonts/misc"
FontPath "/usr/lib/X11/fonts/cyrillic"
FontPath "/usr/lib/X11/fonts/100dpi/:unscaled"
FontPath "/usr/lib/X11/fonts/75dpi/:unscaled"
FontPath "/usr/lib/X11/fonts/Type1"
FontPath "/usr/lib/X11/fonts/CID"
FontPath "/usr/lib/X11/fonts/100dpi"
FontPath "/usr/lib/X11/fonts/75dpi"
EndSection

Section "Module"
Load "bitmap"
Load "dbe"
Load "ddc"
Load "extmod"
Load "freetype"
Load "glx"
Load "int10"
Load "record"
Load "type1"
Load "v4l"
Load "vbe"
EndSection

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "keyboard"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "fr"
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 "Ge-Force_1"
Driver "nvidia"
BusID "PCI:1:0:0"
Option "DPMS"
EndSection

Section "Device"
Identifier "Ge-Force_2"
Driver "nvidia"
BusID "PCI:0:13:0"
Option "DPMS"
EndSection


Section "Monitor"
Identifier "170S4"
Option "DPMS"
HorizSync 30-65
VertRefresh 50-75
Modeline "1280x800@60" 83.91 1280 1312 1624 1656 800 816 824 841
EndSection

Section "Monitor"
Identifier "170S6"
Option "DPMS"
HorizSync 30-65
VertRefresh 50-75
Modeline "1280x800@60" 83.91 1280 1312 1624 1656 800 816 824 841
EndSection

Section "Screen"
Identifier "Image_Gauche"
Device "Ge-Force_2"
Monitor "170S4"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
EndSection

Section "Screen"
Identifier "Image_Droite"
Device "Ge-Force_1"
Monitor "170S6"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024" "1280x960" "1280x854" "1280x800" "1280x768" "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
EndSection

Section "ServerFlags"
Option "xinerama" "on"
EndSection

Section "ServerLayout"
Identifier "Default Layout"
Screen "Image_Gauche"
Screen "Image_Droite" RightOf "Image_Gauche"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
EndSection