First of all I would like to say some thanks to the X.org community. Their work is awesome, and the fact I can make my setup work on entirely X.org components it’s something I never thought possible when XFree86 was still around. I personally think that looking at an Optimus laptop with Intel and Nouveau running is a tremendous achievement.

Now, back to the topic.

My laptop at work is a Dell Latitude E6430. Comes loaded with features and I really like it. Among the various features there’s the fact that this is an Nvidia Optimus enabled laptop, sporting both an Intel video card and an Nvidia one:

$ lspci | grep -i vga
00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09)
01:00.0 VGA compatible controller: NVIDIA Corporation GF108GLM [NVS 5200M] (rev a1)

This one is a muxless laptop of the worst kind: video outputs are connected only to specific chips!

So to use an external HDMI connection at home you need to drive it through the Nvidia card, it doesn’t matter if Optimus is enabled or not. I regularly use it docked with the lid closed, external keyboard and mouse and 2 external monitors connected to the VGA and DVI outputs of the docking station. Basically while I’m at the office it looks like a normal desktop computer; but sometime I need to disconnect it to go on a meeting; and sometimes I use it at home to play games as well.

Guess what? Free drivers, proprietary drivers, UEFI, UEFI secure boot, multi monitor, outputs changing on the fly… all sorts of fun! I’m impressed by the fact that it all works together.

There are four modes on which I can operate the system:

• Optimus enabled, free drivers for both Intel and Nvidia cards
• Optimus enabled, free driver for Intel and proprietary driver for the Nvidia card
• Optimus disabled, free driver for the Nvidia card
• Optimus disabled, proprietary driver for the Nvidia card

Each one has its drawbacks, so let’s explain each setup a bit. At the end of the post I’ve made a table with all the pros and cons of each solution.

My current setup is:

• Fedora 19 x86_64
• Kernel 3.11.1 (stock Fedora)
• Nouveau DDX 1.0.9 (stock Fedora)
• Intel DDX 2.21.12 (stock Fedora)
• Nvidia proprietary drivers 325.15 (from my repository)
• VDPAU library 0.7 (stock Fedora)
• Mesa libraries 9.2 (20130919 prerelease, stock Fedora)

UEFI / legacy bios

If secure boot is enabled; there’s no way to use the proprietary Nvidia driver without fiddling with UEFI keys. The module is built separately from the kernel package; so there’s no way for it to have the same signature as the kernel.

When UEFI is enabled, the free drivers work fine and replace the efifb framebuffer driver with their own; thus giving proper modesetting at the correct resolution and a speedy and responsive terminal.

With the proprietary Nvidia driver, the efifb is not replaced; so the console still operates with it and the Nvidia driver only operates the X part. Unfortunately, using this method, the framebuffer console is slow as hell, the resolution is not optimal, and the EFI framebuffer is never exposed onto external monitors. In my case, pressing CTRL+ALT+Fx jumps me to the console that is shown in the closed laptop lid on the docking station; making it pretty useless.

So if you’re going to use the proprietary driver and you often use the console; make sure you’re using Bios mode and not UEFI. What UEFI could bring you is the Intel Rapid Start Technology which has been included in kernel 3.11; so make your choices depending on what you need.

Optimus disabled

When Optimus is disabled, I can freely use the proprietary Nvidia driver or the free Nouveau driver.

Both solution work; unfortunately performance and feature wise Nouveau cannot compete with the proprietary Nvidia driver.

My main issue is power management; with the Nvidia driver the battery lasts a lot more and the performance difference is abysmal. Nouveau performance is really poor with 3D games (especially Steam commercial ones, with Doom 3 it works fine) and there’s absolutely no power management; at least on my laptop. By playing with performance levels I was only able to overheat the card!

Another thing that does not work with Nouveau is the docking station removal. With the Nvidia proprietary driver I’m able to do the following:

– Disconnect from the docking station: output goes from the external VGA and DVI monitors to the internal LVDS display.

– Reconnect to the docking station: internal LVDS display gets shut off and output goes to VGA and DVI monitors as they were before; one next to the other. I can even close the lid and the computer doesn’t go in standby.

With Nouveau, I’m able to disconnect from the docking station but when reconnecting I need to reconfigure the monitors in their place; and after this, when closing the lid I need to wake up again the computer because it goes on standby.

With the recent Xrandr support to the proprietary drivers I don’t even need to edit che X.org configuration file. Whether I use nvidia-settings or Gnome Displays panel the result is reflected in both implementations and preserved across boots.

Optimus with proprietary Nvidia drivers

To configure Optimus with proprietary drivers perform the following. First of all install the proprietary driver as normal. Now edit the /etc/grub2.cfg file and remove some parameters from the kernel command line. This is required because the Intel driver still need to operate with its KMS driver. So, from this:

nouveau.modeset=0 rd.driver.blacklist=nouveau nomodeset gfxpayload=vga=normal

you should go to this:

nouveau.modeset=0 rd.driver.blacklist=nouveau

After this, edit/recreate the /etc/X11/xorg.conf file with the following contents:

Section "ServerLayout"
    Identifier "layout"
    Screen 0 "nvidia"
    Inactive "intel"
EndSection
 
Section "Device"
    Identifier "intel"
    Driver "intel"
EndSection
 
Section "Screen"
    Identifier "intel"
    Device "intel"
EndSection
 
Section "Device"
    Option "ConstrainCursor" "no"
    Identifier "nvidia"
    Driver "nvidia"
    BusID "PCI:1:0:0"
EndSection
 
Section "Screen"
    Identifier "nvidia"
    Device "nvidia"
    #Option "UseDisplayDevice" "none"
EndSection

Make sure to set the correct bus ID for the Nvidia card; for instructions look in the Nvidia documentation. Contrary to what’s written in the Nvidia documentation I had to use the intel DDX driver for the Intel card instead of the modesetting one. With modesetting I’m not able to get any output on the Intel card.

Upon reboot, you will see KMS running for the Intel card (Plymouth screen) and then the login manager appears on the Nvidia attached panels, while the Intel outputs shut off.

After logging in, you can also check that both drivers are running with the following commands:

$ lsmod | egrep "i915|nvidia"
nvidia               9365874  51 
i915                  651861  2 
i2c_algo_bit           13257  1 i915
drm_kms_helper         50239  1 i915
drm                   274480  5 i915,drm_kms_helper,nvidia
i2c_core               34242  7 drm,i915,i2c_i801,drm_kms_helper,i2c_algo_bit,nvidia,videodev
video                  19104  1 i915

$ dmesg | egrep -i "i915|nvidia"
[    4.589447] nvidia: module license 'NVIDIA' taints kernel.
[    4.595759] nvidia: module verification failed: signature and/or required key missing - tainting kernel
[    4.601728] nvidia 0000:01:00.0: enabling device (0004 -> 0007)
[    4.613153] [drm] Initialized nvidia-drm 0.0.0 20130102 for 0000:01:00.0 on minor 0
[    4.613159] NVRM: loading NVIDIA UNIX x86_64 Kernel Module  325.15  Wed Jul 31 18:50:56 PDT 2013
[    4.738199] i915 0000:00:02.0: setting latency timer to 64
[    4.768878] i915 0000:00:02.0: irq 48 for MSI/MSI-X
[    5.088964] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[    5.088966] i915 0000:00:02.0: registered panic notifier
[    5.088982] i915: No ACPI video bus found
[    5.420554] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 1
[    5.966583] nvidia 0000:01:00.0: irq 50 for MSI/MSI-X
[  198.017862] nvidia 0000:01:00.0: irq 50 for MSI/MSI-X

To light up the other display some xrandr command is required (to enable these at boot add them in /etc/X11/xinit/xinitrc.d):

$ xrandr --setprovideroutputsource Intel NVIDIA-0
$ xrandr --auto
$ xrandr --output VGA1 --left-of DP-1

Your Intel monitor should now have an extended desktop managed by the Nvidia card. Move windows around, and launch some commands to see that wherever you go you’re using the Nvidia accelerated driver:

$ glxinfo| grep "OpenGL version string"
OpenGL version string: 4.3.0 NVIDIA 325.15
$ vdpauinfo | grep -i string
Information string: NVIDIA VDPAU Driver Shared Library  325.15  Wed Jul 31 18:14:57 PDT 2013

Everything seems to work, except output manipulation. Xrandr, Gnome and Nvidia drivers have a different view.

Xrandr view:

$ xrandr -q | grep conn
VGA-0 connected primary 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
LVDS-0 connected (normal left inverted right x axis y axis)
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 connected 1680x1050+1680+0 (normal left inverted right x axis y axis) 474mm x 296mm
HDMI-0 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)

This is what I have in the Nvidia settings panel and in the Gnome Displays panel for the monitors; in one case I don’t see any monitor, in another one I have the internal LVDS display shown as enabled while in reality is not and with the button locked in the “On” position:

Primary monitor assignment does not work as well. I usally have the Gnome panel on the left monitor. If I try to move it from the Nvidia output I get this feedback:

$ xrandr --output VGA1 --primary
X Error of failed request:  BadMatch (invalid parameter attributes)
  Major opcode of failed request:  139 (RANDR)
  Minor opcode of failed request:  30 (RRSetOutputPrimary)
  Serial number of failed request:  53
  Current serial number in output stream:  55

Putting monitor problems aside, running in this mode does not really give any benefit compared to running it with Optimus disabled and the proprietary Nvidia driver installed. Both cards are running with power management, but the Nvidia card is never shut off, so it doesn’t use less power than when running standalone.

There’s no way to turn off the card with vga_switcheroo, all 3d libraries come from the Nvidia drivers and your desktop is being rendered by the Nvidia card.

Prime (Optimus) with free Nouveau drivers

Here comes the juicy part. With enough maturity on the Nouveau side this would be the perfect setup. To start with this implementation; nothing is required, just install Fedora and everything should be already set up. Booting it shows the Plymouth logo on both outputs.

Login in the system, and check that both drivers are running:

$ lsmod | egrep "i915|nouveau"
nouveau               943445  1 
i915                  651861  4 
mxm_wmi                12865  1 nouveau
ttm                    79865  1 nouveau
i2c_algo_bit           13257  2 i915,nouveau
drm_kms_helper         50239  2 i915,nouveau
drm                   274480  8 ttm,i915,drm_kms_helper,nouveau
i2c_core               34242  7 drm,i915,i2c_i801,drm_kms_helper,i2c_algo_bit,nouveau,videodev
wmi                    18697  3 dell_wmi,mxm_wmi,nouveau
video                  19104  2 i915,nouveau

$ dmesg | egrep "i915|nouveau"
[    3.155259] i915 0000:00:02.0: setting latency timer to 64
[    3.163318] nouveau 0000:01:00.0: enabling device (0004 -> 0007)
[    3.185671] i915 0000:00:02.0: irq 45 for MSI/MSI-X
[    3.517135] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[    3.517136] i915 0000:00:02.0: registered panic notifier
[    3.517156] i915: No ACPI video bus found
[    3.774151] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0
[    3.774654] nouveau  [  DEVICE][0000:01:00.0] BOOT0  : 0x0c1e00a1
[    3.774659] nouveau  [  DEVICE][0000:01:00.0] Chipset: GF108 (NVC1)
[    3.774663] nouveau  [  DEVICE][0000:01:00.0] Family : NVC0
[    3.778240] nouveau  [   VBIOS][0000:01:00.0] checking PRAMIN for image...
[    3.787999] nouveau  [   VBIOS][0000:01:00.0] ... signature not found
[    3.788002] nouveau  [   VBIOS][0000:01:00.0] checking PROM for image...
[    3.788086] nouveau  [   VBIOS][0000:01:00.0] ... signature not found
[    3.788087] nouveau  [   VBIOS][0000:01:00.0] checking ACPI for image...
[    4.624674] nouveau  [   VBIOS][0000:01:00.0] ... appears to be valid
[    4.624679] nouveau  [   VBIOS][0000:01:00.0] using image from ACPI
[    4.624845] nouveau  [   VBIOS][0000:01:00.0] BIT signature found
[    4.624850] nouveau  [   VBIOS][0000:01:00.0] version 70.08.a8.00.8d
[    4.625140] nouveau  [ DEVINIT][0000:01:00.0] adaptor not initialised
[    4.625144] nouveau  [   VBIOS][0000:01:00.0] running init tables
[    4.753512] nouveau  [     PFB][0000:01:00.0] RAM type: GDDR5
[    4.753514] nouveau  [     PFB][0000:01:00.0] RAM size: 1024 MiB
[    4.753515] nouveau  [     PFB][0000:01:00.0]    ZCOMP: 0 tags
[    4.779859] nouveau  [  PTHERM][0000:01:00.0] FAN control: none / external
[    4.779863] nouveau  [  PTHERM][0000:01:00.0] fan management: disabled
[    4.779867] nouveau  [  PTHERM][0000:01:00.0] internal sensor: yes
[    4.783179] nouveau  [     DRM] VRAM: 1024 MiB
[    4.783180] nouveau  [     DRM] GART: 1048576 MiB
[    4.783184] nouveau  [     DRM] TMDS table version 2.0
[    4.783185] nouveau  [     DRM] DCB version 4.0
[    4.783199] nouveau  [     DRM] DCB outp 00: 01000323 00010034
[    4.783201] nouveau  [     DRM] DCB outp 01: 020323a6 0f220010
[    4.783202] nouveau  [     DRM] DCB outp 02: 040433b6 0f220010
[    4.783203] nouveau  [     DRM] DCB outp 03: 08024382 00020010
[    4.783204] nouveau  [     DRM] DCB outp 04: 02032362 00020010
[    4.783205] nouveau  [     DRM] DCB outp 05: 04043372 00020010
[    4.783206] nouveau  [     DRM] DCB outp 06: 02011300 00000000
[    4.783207] nouveau  [     DRM] DCB conn 00: 00000041
[    4.783209] nouveau  [     DRM] DCB conn 01: 00000100
[    4.783210] nouveau  [     DRM] DCB conn 02: 00001246
[    4.783211] nouveau  [     DRM] DCB conn 03: 00002346
[    4.783212] nouveau  [     DRM] DCB conn 04: 00010461
[    4.783213] nouveau  [     DRM] DCB conn 05: 00000500
[    4.783878] nouveau  [     DRM] ACPI backlight interface available, not registering our own
[    4.784072] nouveau  [     DRM] 3 available performance level(s)
[    4.784075] nouveau  [     DRM] 0: core 50MHz shader 101MHz memory 135MHz voltage 830mV
[    4.784076] nouveau  [     DRM] 1: core 202MHz shader 405MHz memory 324MHz voltage 830mV
[    4.784078] nouveau  [     DRM] 3: core 672MHz shader 1344MHz memory 1569MHz voltage 980mV
[    4.784079] nouveau  [     DRM] c: core 202MHz shader 405MHz memory 324MHz
[    4.789392] nouveau  [     DRM] MM: using COPY0 for buffer copies
[    4.925967] nouveau  [     DRM] allocated 1680x1050 fb: 0x60000, bo ffff88021fc21400
[    4.926065] nouveau 0000:01:00.0: fb1: nouveaufb frame buffer device
[    4.926068] [drm] Initialized nouveau 1.1.1 20120801 for 0000:01:00.0 on minor 1

Poking around with xrandr will give you totally different outputs from the Nvidia driver:

$ xrandr -q | grep conn
LVDS1 connected (normal left inverted right x axis y axis)
VGA1 connected primary 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
LVDS-2 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 connected 1680x1050+1680+0 (normal left inverted right x axis y axis) 474mm x 296mm
HDMI-1 disconnected (normal left inverted right x axis y axis)
VGA-2 disconnected (normal left inverted right x axis y axis)

But at least they’re consistent with the Gnome Displays panel:

For reasons I don’t understand the Nvidia card appears twice in 2 different but identical providers:

$ xrandr --listproviders
Providers: number : 3
Provider 0: id: 0x96 cap: 0xb, Source Output, Sink Output, Sink Offload crtcs: 3 outputs: 2 associated providers: 2 name:Intel
Provider 1: id: 0x66 cap: 0x7, Source Output, Sink Output, Source Offload crtcs: 2 outputs: 5 associated providers: 2 name:nouveau
Provider 2: id: 0x66 cap: 0x7, Source Output, Sink Output, Source Offload crtcs: 2 outputs: 5 associated providers: 2 name:nouveau

With the tests I made, there’s no apparent difference when using one or the other. Usage of one card or the other is driven by the DRI_PRIME environment variable. If it’s set to 0, commands run on the Intel card, if it’s set to 1 they will run on the Nvidia card. For example:

$ DRI_PRIME=1 vdpauinfo | grep -i string
Information string: G3DVL VDPAU Driver Shared Library version 1.0

Or even better, to check OpenGL status:

$ glxinfo | grep -e 'OpenGL.*string.*'
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Ivybridge Mobile 
OpenGL core profile version string: 3.1 (Core Profile) Mesa 9.2.0
OpenGL core profile shading language version string: 1.40
OpenGL version string: 3.0 Mesa 9.2.0
OpenGL shading language version string: 1.30

$ DRI_PRIME=1 glxinfo | grep -e 'OpenGL.*string.*'
OpenGL vendor string: nouveau
OpenGL renderer string: Gallium 0.4 on NVC1
OpenGL core profile version string: 3.1 (Core Profile) Mesa 9.2.0
OpenGL core profile shading language version string: 1.40
OpenGL version string: 3.0 Mesa 9.2.0
OpenGL shading language version string: 1.30

Unfortunately the desktop is very slow, it’s rendered by the Intel driver and put on the Nvidia card for display. I’ve tried changing priority in vga_switcheroo prior to starting X, setting the DRI_PRIME=1 variable at boot, use xrandr to change the provider output source etc. to no avail; the desktop can run only on the first card or it doesn’t work. Usually I get a black screen upon GDM start.

There’s no power management as well, so the Intel card runs normally but the Nvidia one is always on and stuck in an intermediate performance level.

When docking it; I get cloned outputs on all external displays at a very low resolution. Same issue with the Optimus disabled Nouveau driver; the outputs need to be rearranged, the lid closed and the computer needs to be woken up from standby.

Optimus cards power operation

Dual cards can be shut down on demand through vga_switcheroo. For example, login in your system as root without X running. Look at the card status with the following command:

# cat /sys/kernel/debug/vgaswitcheroo/switch
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :Pwr:0000:01:00.0

This will tell you that the Integrated Graphics Display (IGD) is powered up (Pwr) and that is the primary display (+). To shut off the secondary video card, a single command is required:

# echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
# cat /sys/kernel/debug/vgaswitcheroo/switch
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :Off:0000:01:00.0

This will shutdown the Nvidia card. A look at the battery will tell you now that you have twice the power because the Intel card sucks very little power compared to the Nvidia one.

Turn the card on again, and switch the framebuffer console to it:

# echo ON > /sys/kernel/debug/vgaswitcheroo/switch
# cat /sys/kernel/debug/vgaswitcheroo/switch
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :Pwr:0000:01:00.0
# echo DDIS > /sys/kernel/debug/vgaswitcheroo/switch
[  879.436727] i915: switched off
# cat /sys/kernel/debug/vgaswitcheroo/switch
0:IGD: :Off:0000:00:02.0
1:DIS:+:Pwr:0000:01:00.0

This will move the framebuffer and your shell to the other Nvidia driven monitor and shut down the Intel card. Sweet, isn’t it?

Power management for automatic powerup/shutdown of cards in Optimus systems and runtime management will come in kernel 3.12; I’ve tested it by using the Fedora Rawhide kernel repository and the situation improves a lot:

# cat /sys/kernel/debug/vgaswitcheroo/switch 
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :DynPwr:0000:01:00.0

As you can see the second card is dynamically powered. Try to undock the system and check the status again: the second output is no longer needed so the second card shuts off:

# cat /sys/kernel/debug/vgaswitcheroo/switch 
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :DynOff:0000:01:00.0

Now, with the laptop undocked, launch a command on the second card:

# DRI_PRIME=1 vdpauinfo | grep -i string
Information string: G3DVL VDPAU Driver Shared Library version 1.0
# cat /sys/kernel/debug/vgaswitcheroo/switch 
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :DynPwr:0000:01:00.0

You will notice a slight delay before the command output is returned, but the card is powered on again! This is awesome. Now, after 1 or 2 seconds look again at the card:

# cat /sys/kernel/debug/vgaswitcheroo/switch 
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :DynOff:0000:01:00.0

It’s shut off! Dock the laptop again and the monitor should come up again.

Keep in mind that powering up and down cards is a totally different things than power managing and adjusting clocks etc. for a running card. This make the Nvidia card shutdown automatically, not regulate its power levels during usage.

Summary

A Prime enabled laptop does not have any configuration and does not require any manual configuration. The fact that the Nvidia card can power down itself is great and doubles my battery duration! On the screen I have KMS consoles without huge fonts and can have UEFI secure boot enabled! This is really awesome.

Unfortunately though, without proper Nouveau power management and performance improvements added to the fact that I need to reconfigure monitors everytime I move (sometime the output gets all black as well when docking); the experience is not that great. I don’t know why, but when I’m undocked and using only the LVDS internal panel, the Intel performance is fantastic. Problems arise only when it’s docked and Nouveau is enabled as well.

My old laptop was working flawlessly with Nouveau. I didn’t play games on it, it was not Optimus based and the driver was generally working better.

Summing up, my current choice is for the Optimus disabled setup with Nvidia drivers. I can play games, dock, undock, power management works ok and I can drive all outputs easily. And if I need to go in a meeting I don’t need to be extra cautious in shutting down virtual machines, because the system might not go up again. It’s kinda retro style when booting with the text console and battery does not last more than 3 hours, but I can bear it.

I’m impressed by the current X.org improvements of the last years and really looking forward to new developments. Sometimes just for fun I often switch back to the free drivers to check the status; like the new dynamic power management in kernel 3.12.

Let’s hope Nvidia collaboration becomes better and the new documentation does not simply stop to what has been announced.