Merci de tes conseils azrael cela fonctionne.... presque.
disons que maintenant j'ai un pc utilisable tant que je n'active pas la carte Nvidia.
quand je lance par exemple la commande
optirun glxspheres
[ 1313.463994] [ERROR]Cannot access secondary GPU - error: [XORG] (EE) /dev/dri/card1: failed to set DRM interface version 1.4: Permission denied
[ 1313.464060] [ERROR]Aborting because fallback start is disabled.
sinon comme config software de bunblebee j'ai
bbswitch-dkms-0.8.0-2.fc23.x86_64
bumblebee-release-1.2-1.noarch
bumblebee-3.2.1-9.fc23.x86_64
bumblebee-nouveau-1.1.0-4.fc23.noarch
et le statut de bumblebee est
systemctl -l status bumblebeed.service
● bumblebeed.service - Bumblebee C Daemon
Loaded: loaded (/usr/lib/systemd/system/bumblebeed.service; enabled; vendor preset: disabled)
Active: active (running) since sam. 2015-12-26 16:55:44 CET; 27min ago
Main PID: 887 (bumblebeed)
CGroup: /system.slice/bumblebeed.service
└─887 /usr/sbin/bumblebeed
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207310] [WARN][XORG] (WW) Warning, couldn't open module mouse
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207314] [ERROR][XORG] (EE) Failed to load module "mouse" (module does not exist, 0)
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207322] [ERROR][XORG] (EE) No devices detected.
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207325] [ERROR][XORG] (EE)
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207328] [ERROR][XORG] (EE) no screens found(EE)
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207331] [ERROR][XORG] (EE)
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207335] [ERROR][XORG] (EE) Please also check the log file at "/var/log/Xorg.8.log" for additional information.
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207338] [ERROR][XORG] (EE)
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207341] [ERROR][XORG] (EE) Server terminated with error (1). Closing log file.
déc. 26 17:17:52 grocanar bumblebeed[887]: [ 1334.207656] [ERROR]X did not start properly
je continue de creuser l affaire.