~]$ optirun nvidia-settings -c :8
... [ERROR]Cannot access secondary GPU - error: [XORG] (EE) No devices detected
... [ERROR]Aborting because fallback start is disabled.

# cat /proc/acpi/bbswitch
0000:01:00:00.0 OFF

lsmod | grep nvidia

Name           : xf86-video-intel
Version        : 2.21.15-1
Description    : X.org Intel i810/i830/i915/945G/G965+ video drivers
Architecture   : x86_64
URL            : http://xorg.freedesktop.org/
Licenses       : custom
Groups         : xorg-drivers  xorg
Provides       : xf86-video-intel-uxa  xf86-video-intel-sna
Depends On     : intel-dri  libxvmc  pixman  xcb-util>=0.3.9
Optional Deps  : None
Required By    : None
Optional For   : None
Conflicts With : xorg-server<1.14.0  X-ABI-VIDEODRV_VERSION<14  X-ABI-VIDEODRV_VERSION>=15  xf86-video-intel-sna  xf86-video-intel-uxa  xf86-video-i810  xf86-video-intel-legacy
Replaces       : xf86-video-intel-uxa  xf86-video-intel-sna
Installed Size : 1733.00 KiB
Packager       : Laurent Carlier <lordheavym@gmail.com>
Build Date     : Wed Aug 21 21:25:27 2013
Install Date   : Thu Sep 12 03:28:08 2013
Install Reason : Explicitly installed
Install Script : Yes
Validated By   : SHA256 Sum
 

[  114.065312] [ERROR]Cannot access secondary GPU - error: [XORG] (EE) No devices detected.
[  114.065990] [ERROR]Aborting because fallback start is disabled.

bumblebeed.service - Bumblebee C Daemon
   Loaded: loaded (/usr/lib/systemd/system/bumblebeed.service; enabled)
   Active: active (running) since Mon 2013-09-16 06:20:08 YEKT; 3min 18s ago
 Main PID: 288 (bumblebeed)
   CGroup: name=systemd:/system/bumblebeed.service
           ΓööΓöÇ288 /usr/bin/bumblebeed
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065138] [WARN][XORG] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/100dpi/".
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065170] [WARN][XORG] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/75dpi/".
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065199] [ERROR][XORG] (EE) No devices detected.
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065206] [ERROR][XORG] (EE)
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065211] [ERROR][XORG] (EE) no screens found(EE)
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065216] [ERROR][XORG] (EE)
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065221] [ERROR][XORG] (EE) Please also check the log file at "/var/log/Xorg.8.log" for additional information.
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065225] [ERROR][XORG] (EE)
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065229] [ERROR][XORG] (EE) Server terminated with error (1). Closing log file.
Sep 16 06:22:00 pampas bumblebeed[288]: [  114.065233] [ERROR]X did not start properly 

Name           : bumblebee
Version        : 3.2.1-3
Description    : NVIDIA Optimus support for Linux through VirtualGL
Architecture   : x86_64
URL            : http://www.bumblebee-project.org
Licenses       : GPL3
Groups         : None
Provides       : nvidia-libgl
Depends On     : virtualgl  glib2  mesa-libgl
Optional Deps  : xf86-video-nouveau: nouveau driver [installed]
                 nouveau-dri: 3D acceleration features fo nouveau [installed]
                 bbswitch: switch on/off discrete card
                 nvidia: NVIDIA kernel driver
                 primus: faster back-end for optirun [installed]
                 lib32-virtualgl: run 32bit applications with optirun [installed]
                 lib32-primus: faster back-end for optirun
Required By    : primus
Optional For   : None
Conflicts With : nvidia-libgl
Replaces       : None
Installed Size : 185.00 KiB
Packager       : Sven-Hendrik Haase <sh@lutzhaase.com>
Build Date     : Fri May 17 05:57:07 2013
Install Date   : Mon Sep  9 00:23:08 2013
Install Reason : Explicitly installed
Install Script : Yes
Validated By   : SHA256 Sum
 

# echo ON >> /proc/acpi/bbswitch

# modprobe nvidia
Module 'nvidia' is not found.

 # bumblebeed -v --debug]

# bumblebeed -v --debug &> bumblebee.log &
[  161.795848] [INFO]Configured driver: nvidia
[  161.797787] [DEBUG]bbswitch has been detected.
[  161.798034] [INFO]Switching method 'bbswitch' is available and will be used.
[  161.798170] [DEBUG]Active configuration:
[  161.798273] [DEBUG] bumblebeed config file: /etc/bumblebee/bumblebee.conf
[  161.798376] [DEBUG] X display: :8
[  161.798478] [DEBUG] LD_LIBRARY_PATH: /usr/lib/nvidia:/usr/lib32/nvidia
[  161.798581] [DEBUG] Socket path: /var/run/bumblebee.socket
[  161.798683] [DEBUG] xorg.conf file: /etc/bumblebee/xorg.conf.nvidia
[  161.798785] [DEBUG] xorg.conf.d dir: /etc/bumblebee/xorg.conf.d
[  161.798887] [DEBUG] ModulePath: /usr/lib/nvidia/xorg/,/usr/lib/xorg/modules
[  161.801446] [DEBUG] GID name: bumblebee
[  161.801558] [DEBUG] Power method: auto
[  161.801672] [DEBUG] Stop X on exit: 1
[  161.801783] [DEBUG] Driver: nvidia
[  161.801892] [DEBUG] Driver module: nvidia
[  161.802001] [DEBUG] Card shutdown state: 1
[  161.802214] [  161.802279] [DEBUG]Hiding stderr for execution of /sbin/modprobe
[  161.803601] [DEBUG]SIGCHILD received, but wait failed with No child processes
[  161.803742] [ERROR]Module 'nvidia' is not found. 

00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09)
01:00.0 VGA compatible controller: NVIDIA Corporation GF108M [GeForce GT 635M] (rev a1)