(X)ubuntu Linux 14.04 on Asus N550JK laptop

I've just acquired a new work laptop (Asus N550JK-CM604H) and for my job the first step was getting my preferred Linux distro (Xubuntu 14.04 LTS) up and running on it. However, the laptop is newer than the distro release, so I didn't expect it to all be smooth sailing...

The hardware

Intel i7-4720HQ: 2.6 GHz (3.6 GHz turbo), 4 cores, 8 threads, 6MB cache
2x4GB DDR3 1600 MHz (replaced with 2x8GB)

NVIDIA Optimus dual GPU setup:

  • Intel HD 4600, by default using 64MB of system memory as VRAM.
  • NVIDIA GeForce 850M, 2GB dedicated VRAM

HDMI and mini-DisplayPort external outputs. By default everything goes through Intel GPU; see below for NVIDIA Optimus support.

15.6" LED-backlit 1080p IPS
Hard drive
Seagate Momentus ST1000LM024: 1TB SATA-II 5400rpm (replaced with Samsung 850 EVO 500GB)
Wired network
Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller; supported by r8169 driver without intervention
Wireless network
Intel 7260; supported by iwlwifi driver without intervention
FocalTech touchpad; see below
Atmel maXTouch Digitizer; using evdev without intervention
It's a keyboard; see below for details of function keys
Generic USB video class (UVC) 720p webcam; works without intervention (tested in camorama)
Intel High-Definition Audio; using snd_hda_intel without intervention

LTS Hardware Enablement Stack (HWE)

When using an older Linux distro release on a brand new machine, it's likely that some things won't be very well supported by whichever kernel and Xorg versions that release froze on. Ubuntu's answer to the problem is the LTS Hardware Enablement Stack. At the time of writing, the stack based on 15.04 (Vivid) was the latest, so the following command was used:

sudo apt-get install --install-recommends \
    linux-generic-lts-vivid xserver-xorg-core-lts-vivid xserver-xorg-lts-vivid \
    xserver-xorg-video-all-lts-vivid xserver-xorg-input-all-lts-vivid \

The only problem with this is that some packages might not be able to build drivers against the new kernel. I found this to be the case for VirtualBox, but using the latest version available from the VirtualBox site gets around this.


I decided to try out suspend and resume early on, since historically it's been a fairly quirky area of hardware support. In this case, the nouveau driver barfed into the logs and prevented sleep. Blacklisting it seems to fix the problem: add blacklist nouveau to /etc/modprobe.d/blacklist-nouveau.conf. This was no big deal, since I'm either using the Intel GPU or the proprietary NVIDIA drivers.

Graphics driver

Like a lot of decent modern laptops, this one has a dual-GPU setup: the Intel HD 4600 as part of the CPU, and an NVIDIA 850M.

As is to be expected, the Intel GPU just works. The HWE upgrade enabled DisplayPort 1.2 Multi-Stream Transport (MST) support, which allowed me to daisy-chain my Dell U2515H monitors which support this feature. (Note: the monitors ship with this feature disabled, you need to enable it in the OSD on each monitor.)

The NVIDIA GPU was less straightforward: at the time of installing, the latest NVIDIA drivers in the Ubuntu 14.04 repos would not build against the 3.19 kernel from 15.04. Luckily, the backported newer drivers were added within a couple of weeks.

There are two ways to enable NVIDIA support on a laptop like this: using "Bumblebee" to allow per-application use of the NVIDIA GPU, or using "NVIDIA Prime" to switch the entire desktop environment between GPUs (requires logging out and back in again). Because I don't intend to make much use of the NVIDIA GPU, I opted for the latter:

sudo apt-get install nvidia-346-updates nvidia-prime

By default the Intel GPU should remain selected. The GPU can be switched from the nvidia-settings control panel.

Touchpad driver

The laptop has a FocalTech touchpad, which I hadn't heard of before, and which isn't handled properly even in the 3.19 kernel from Ubuntu 15.04. Luckily, these touchpads seem to be used in multiple Asus laptops now, and Ask Ubuntu had an answer: Asus X750JA and Ubuntu Gnome 14.04. Following those instructions and rebooting, the touchpad had gained two-finger vertical scrolling, edge scrolling, and also the ability to use synclient to tweak the settings.

In terms of customising the touchpad behaviour, I put the following in my ~/.xprofile:

synclient HorizTwoFingerScroll=1 \
          VertEdgeScroll=0 \
          TapButton3=2 \
  • Enable 2-finger scrolling horizontally (vertical 2-finger scroll is enabled by default)
  • Disable vertical edge scrolling, since I'm just going to be using 2-finger scrolling all the time
  • Turn 3-finger taps into a "middle button" click (2-finger taps are "right click" by default)
  • Enable palm detection, to try and get rid of spurious inputs when typing


It's a keyboard. It generally works as well as you'd expect for one of the oldest standard bits of computer hardware. What tends to vary these days is of course the special/"fn" keys on the keyboard. This one has several. Going left-to-right, top-to-bottom:

Sleep key
Is recognised by power management functionality: if you have it set to suspend when the sleep button is pressed, pressing this key will suspend the same as via any other route.
Wireless toggle
Not registered at all; see below for fix.
Decrease/increase display brightness
Not registered at all; see below for fix.
Toggle display
Seems to switch the laptop screen off and on, not sure where this is handled.
Select display mode
This key is horrible. Really really horrible. So horrible it needs its own subsection (see below). Needless to say, it doesn't work properly.
Toggle touchpad
Recognised as XF86TouchpadToggle, but nothing actually uses it.
Mute/increase/decrease volume
Recognised and behave as expected.
Box with an "S" in it?
Recognised as XF86Launch1.
Recognised as XF86WebCam.
Running person?
Recognised as XF86Launch6.
Recognised as XF86AudioStop, XF86AudioPrev, XF86AudioPlay and XF86AudioNext.
Launches calculator.

Wireless toggle and display brightness

Out of the box, the display brightness and wireless toggle keys are completely unrecognised and generate no events. It seems that this is a bit of ACPI quirkiness that is documented here: Fixing Display Backlight Hotkeys on ASUS N550JK. The TL;DR is:

  • add acpi_osi= to your GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub
  • run sudo update-grub
  • reboot

That horrible "Select display mode" key

In Windows, there is a Win + P combination that opens a quick display selector (for handling an external monitor). This key seems to try and emulate pressing this key combination. When you press Fn + F8 to use this function, it seems to emit the following keycode events:

  • 133 down
  • 33 down
  • 33 up
  • 133 up

Keycode 133 is known as Super_L in Linux, or the left Windows key in common parlance. Keycode 33 is the P key. But those are keycode events, which means if you use an alternative keyboard layout (e.g. Dvorak) you get a different effect (e.g. Win+L). I give up on doing anything useful with this key.

Final words

The laptop makes a pretty adequate desktop replacement, and all of the hardware should be well-supported by an up-to-date Linux distro. However, for those that opt for a long-term stable releases, I hope documenting the quirks I encountered will help somebody in a similar situation.