Xorg.0.log :
5.975] (==) ModulePath set to "/usr/lib/xorg/modules"
[ 5.975] (WW) Hotplugging is on, devices using drivers 'kbd', 'mouse' or 'vmmouse' will be disabled.
[ 5.975] (WW) Disabling Keyboard0
[ 5.975] (WW) Disabling Mouse0
[ 5.975] (II) Loader magic: 0x7ff1d36e2d80
[ 5.975] (II) Module ABI versions:
[ 5.975] X.Org ANSI C Emulation: 0.4
[ 5.975] X.Org Video Driver: 18.0
[ 5.975] X.Org XInput driver : 21.0
[ 5.975] X.Org Server Extension : 8.0
[ 5.976] (II) xfree86: Adding drm device (/dev/dri/card0)
[ 5.978] (--) PCI:*(0:0:2:0) 8086:0166:17aa:21f5 rev 9, Mem @ 0xf1400000/4194304, 0xe0000000/268435456, I/O @ 0x00006000/64
[ 5.978] (II) LoadModule: "glx"
[ 5.978] (II) Loading /usr/lib/xorg/modules/linux/libglx.so
[ 5.989] (II) Module glx: vendor="NVIDIA Corporation"
[ 5.989] compiled for 4.0.2, module version = 1.0.0
[ 5.989] Module class: X.Org Server Extension
[ 5.989] (II) NVIDIA GLX Module 340.46 Wed Sep 24 13:54:14 PDT 2014
[ 5.989] (II) LoadModule: "nvidia"
[ 5.989] (II) Loading /usr/lib/xorg/modules/drivers/nvidia_drv.so
[ 5.990] (II) Module nvidia: vendor="NVIDIA Corporation"
[ 5.990] compiled for 4.0.2, module version = 1.0.0
[ 5.990] Module class: X.Org Video Driver
[ 5.990] (II) NVIDIA dlloader X Driver 340.46 Wed Sep 24 13:34:03 PDT 2014
[ 5.990] (II) NVIDIA Unified Driver for all Supported NVIDIA GPUs
[ 5.990] (++) using VT number 7
[ 5.990] (EE) No devices detected.
[ 5.990] (EE)
Fatal server error:
[ 5.990] (EE) no screens found(EE)
[ 5.990] (EE)
Please consult the The X.Org Foundation support
at
http://wiki.x.org for help.
[ 5.990] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
PS3 : sous Ubuntu ils n'utilisent pas du tout de fichier xorg.conf ,devenu optionnel dans les cas simples depuis quelque temps. J'ai enrichi celui genere par nvidia-xconfig