lanciando glxgears ho praticamente solo 200.000 FPS.

devo installare qualche driver particolare???

il file XF86Config-4 è questo:

# XF86Config-4 (XFree86 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 XF86Config-4 manual page.
# (Type "man XF86Config-4" at the shell prompt.)
#
# This file is automatically updated on xserver-xfree86 package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xfree86
# 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/XF86Config-4 /etc/X11/XF86Config-4.custom
# md5sum /etc/X11/XF86Config-4 >/var/lib/xfree86/XF86Config-4.md5sum
# dpkg-reconfigure xserver-xfree86

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/Speedo"
FontPath "/usr/lib/X11/fonts/100dpi"
FontPath "/usr/lib/X11/fonts/75dpi"
EndSection

Section "Module"
Load "GLcore"
Load "bitmap"
Load "dbe"
Load "ddc"
Load "dri"
Load "extmod"
Load "freetype"
Load "glx"
Load "int10"
Load "record"
Load "speedo"
Load "type1"
Load "vbe"
Load "xtt"
EndSection

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "keyboard"
Option "CoreKeyboard"
Option "XkbRules" "xfree86"
Option "XkbModel" "pc101"
Option "XkbLayout" "it"
EndSection

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

Section "Device"
Identifier "radeon 7500 mobility"
#Driver "ati"
Driver "radeon"
Option "UseFBDev" "true"
Option "AGPFastWrite" "true"
Option "EnablePageFlip" "true"
Option "AGPMode" "4"
#Driver "vesa"
#Option "TVOut" "1"
#Option "TVStandard" "PAL-B"
#VideoRam 32000
EndSection

Section "Monitor"
Identifier "compaq"
HorizSync 30-60
VertRefresh 50-90
Option "DPMS"
EndSection

Section "Screen"
Identifier "Default Screen"
Device "radeon 7500 mobility"
Monitor "compaq"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1024x768"
EndSubSection
SubSection "Display"
Depth 4
Modes "1024x768"
EndSubSection
SubSection "Display"
Depth 8
Modes "1024x768"
EndSubSection
SubSection "Display"
Depth 15
Modes "1024x768"
EndSubSection
SubSection "Display"
Depth 16
Modes "1024x768"
EndSubSection
SubSection "Display"
Depth 24
Modes "1024x768"
EndSubSection
EndSection

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

Section "DRI"
Mode 0666
EndSection

HELP