Hi,

gpu-manager.log attached.


trusty$ dpkg -l | grep -E 'nvidia-|ubuntu-drivers-common'
ii  nvidia-331                 331.38-0ubuntu7    amd64
ii  nvidia-libopencl1-331      331.38-0ubuntu7    amd64
ii  nvidia-opencl-icd-331      331.38-0ubuntu7    amd64
ii  nvidia-prime               0.6.2		  amd64
ii  nvidia-settings            331.20-0ubuntu8    amd64
ii  ubuntu-drivers-common      1:0.2.91.6	  amd64

/var/log/gpu-manager.log:
1st try: bbswitch without quirks
Loading bbswitch with "load_state=-1 unload_state=1" parameters
2nd try: bbswitch with quirks
Loading bbswitch with "load_state=-1 unload_state=1 skip_optimus_dsm=1" parameters
Error: can't load bbswitch
Selecting mesa


X.log.0:
[    18.641] (II) LoadModule: "nvidia"
[    18.641] (WW) Warning, couldn't open module nvidia
[    18.641] (II) UnloadModule: "nvidia"
...
[    18.653] (II) LoadModule: "nvidia"
[    18.653] (WW) Warning, couldn't open module nvidia
[    18.653] (II) UnloadModule: "nvidia"
[    18.653] (II) Unloading nvidia
[    18.653] (EE) Failed to load module "nvidia" (module does not exist, 0)
[    18.653] (II) LoadModule: "nouveau"
[    18.653] (II) Loading /usr/lib/xorg/modules/drivers/nouveau_drv.so
[    18.653] (II) Module nouveau: vendor="X.Org Foundation"
[    18.653]    compiled for 1.15.0, module version = 1.0.10
[    18.653]    Module class: X.Org Video Driver
[    18.653]    ABI class: X.Org Video Driver, version 15.0
[    18.653] (II) UnloadModule: "nouveau"
[    18.653] (II) Unloading nouveau
[    18.653] (II) Failed to load module "nouveau" (already loaded, 0)


`nvidia-settings` still fails with:
"""
** Message: PRIME: Requires offloading
** Message: PRIME: is it supported? yes

ERROR: 
"""

dmesg:
[   13.189063] nvidia: module license 'NVIDIA' taints kernel.
[   13.189065] Disabling lock debugging due to kernel taint
[   13.191827] nvidia: module verification failed: signature and/or  required key missing - tainting kernel
[   13.195308] nvidia 0000:01:00.0: enabling device (0000 -> 0003)
[   13.195360] vgaarb: device changed decodes: PCI:0000:01:00.0,olddecodes=io+mem,decodes=none:owns=none
[   13.195383] snd_hda_intel 0000:00:1b.0: irq 48 for MSI/MSI-X
[   13.195463] [drm] Initialized nvidia-drm 0.0.0 20130102 for 0000:01:00.0 on minor 0
[   13.195469] NVRM: loading NVIDIA UNIX x86_64 Kernel Module  331.38  Wed Jan  8 19:32:30 PST 2014
...
[   17.240234] init: failsafe main process (768) killed by TERM signal
[   17.693825] bbswitch: version 0.7
[   17.693830] bbswitch: Found integrated VGA device 0000:00:02.0: \_SB_.PCI0.GFX0
[   17.693844] bbswitch: cannot find ACPI handle for VGA device 0000:01:00.0
[   17.693845] bbswitch: No discrete VGA device found
[   17.706786] bbswitch: version 0.7
[   17.706789] bbswitch: Found integrated VGA device 0000:00:02.0: \_SB_.PCI0.GFX0
[   17.706791] bbswitch: cannot find ACPI handle for VGA device 0000:01:00.0
[   17.706792] bbswitch: No discrete VGA device found
[   18.655591] ip_tables: (C) 2000-2006 Netfilter Core Team
[   27.700868] init: Failed to spawn nvidia-persistenced main process: unable to execute: No such file or directory
[   37.705234] init: Failed to spawn nvidia-persistenced main process: unable to execute: No such file or directory

$ lspci | grep VGA   
00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor Graphics Controller (rev 09)
01:00.0 VGA compatible controller: NVIDIA Corporation G94 [GeForce 9600 GT] (rev a1)

$ lsmod | grep -E 'nv|drm'
nvidia              10675249  1 
drm_kms_helper         53081  1 i915
drm                   303102  5 i915,drm_kms_helper,nvidia


thanks,
Hamish