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The ThinkPad X1 Carbon 6th Gen (2018)

WARNING (April 2020): Lenovo/Intel have dropped support for 5k resolutions (e.g. 5120 x 1440); this was confirmed by the technical support team.

I settled on the Lenovo ThinkPad X1 Carbon because Thinkpad’s have good history of Linux support, and in particular on the X1 Carbon line because it is lightweight and small. That actually matters because I’ll be carrying it around for work every day.

This is an incredibly small and lightweight 14” laptop, and it makes very few sacrifices to get there. Perhaps, the only dongle you might choose to carry is an Ethernet adaptor.

I’m generally happy with it. I’m going to outline and review the hardware in this article, and, in a separate article, describe how I set it up with Arch Linux.

Firstly, a collection of useful links:

We may want to be aware of the Lenovo Superfish incident, and a few other incidents that may cause us to mistrust Lenovo. However, I believe these did not affect the business line of laptops (certainly Superfish did not).

Hardware

Let’s take a detailed look at the hardware of my chosen variant:

  • Intel i7-8550U CPU (Intel 8th Gen; late-2017 Kaby Lake Refresh, 14nm).
    • 4-core, 8 threads.
    • 1.8 Ghz base clock.
    • 3.7 Ghz 4-core turbo, and 4.0 Ghz 2-core turbo—good luck sustaining these speeds though!
    • VT-x, VT-d (both for virtualisation), and AVX2.
    • 23 W continuous TDP, and 29 W turbo TDP. (Possibly 15 W on Linux.)
    • No IPC improvements over 7th Gen processors.
  • Intel UHD 620 integrated GPU.
    • Hardware-accelerated video:
      • Supports 8/10-bit and 4k HEVC/H.265 Main10 and VP9 Profile2 codecs (encode & decode, except only VP9 Profile0 encode.)
        • VP9 is useful for YouTube.
      • MPEG-2/H.262 1080p & MPEG-4/H.264 4k encode/decode
      • JPEG encode/decode 16x16k
      • HDCP 2.2 :/
    • Very bad for gaming, especially at 1440p… Even though half the chip’s area is devoted to the GPU!
  • 16GB Single DIMM LPDDR3 2133 Mhz RAM (there is only one slot).
  • 512GB Opal 2 (SED) TLC PCIe SSD (Samsung SM981/PM981).
  • 57 Wh battery.
    • With “RapidCharge”: 0–80% in one hour.
  • 2 x 1 Watt “Dolby Premium Audio” speakers.
    • Downward firing at the front-bottom of the laptop.
    • These are not very “premium” at all, in particular the bass is very lacklustre.
  • 360° Noise-cancelling Dual Array Far Field Microphones.
    • At the top of the screen, near the camera.
  • Intel Dual-Band Wireless-AC 2 x 2, Bluetooth 4.2 [8265/8275 Rev 21]. (Wireless LAN is upgradeable).
    • Self-upgradable to Wireless-AC 9260:
      • 9260 Wi-Fi supports 160 Mhz channels on the 5 Ghz band (~1.73 Gb/s vs 867 Mb/s), in practise this makes no difference.
      • 9260 offers Bluetooth 5.0.
        • (Longer range OR speed).
        • Play on two devices simultaneously.
        • Audio may be better with aptX (but this may not be supported?!).
    • Self-upgradable to Wi-Fi 6 AX200:
      • In addition to Wireless-AC 9260, this offers Wi-Fi 6.
  • 2 x USB 3.0.
  • 2 x Thunderbolt 3 (USB Type-C).
  • SD Card Reader (SD, MMC, SDHC, SDXC).
    • Without CPRM (Content Protection for Recordable Media).
    • Spring-insertion towards the bottom-edge of the laptop once the tray is pulled out
  • 1 x HDMI 1.4a port.
  • Native Ethernet support via dongle. Intel I219-V (Rev 21).
    • Supporting MAC address pass-through.
  • 720p camera with manual shutter.
  • The empty WWAN slot can used as a second, smaller M.2-2242 Drive.
  • Integrated fingerprint reader which does not work on Linux.
  • 14” 1440p HDR (500 nits) glossy IPS with Dolby Vision.
    • Please use an ICC profile, or whatever your OS/applications need to display colours accurately on this very nice display.
  • 323.5 mm x 217.1 mm x 15.95 mm, 1.13 kg.

The differences between variants include: the particular 8th Gen CPU (the biggest difference here is support for vPro and Trusted Execution rather than performance), the size of the single DIMM RAM, the size of the SSD, the quality of the display (color gamut, matt vs glossy, and resolution), support for NFC, IR camera, and WWAN antennas + card (you don’t get the antennas if you don’t choose WWAN).

Connectivity and Ports

Left Side:

  • 2 x USB-C Thunderbolt 3 + Power Connectors
  • Ethernet extension connector (for dongle) / Docking Station Connector
  • USB 3.0 Type-A
  • HDMI 1.4a

Right Side:

  • Kensington Lock
  • USB 3.0 Type-A (always-on charging)
  • Headphones/Microphones combo (3.5 mm, 4-pole plug)

Back Edge:

  • SD/Sim—pull out tray, no pin required

Underside:

  • The holes are for positioning with the docking station.
  • There is an emergency reset hole, if you cannot turn the laptop off using the power button.
    • To use it: first remove the power cable, then insert a paper clip.

Top of Display:

  • The camera.
    • A white light will indicate that it is “in-use”.
    • In contrast, red lights on the F1 & F4 keys indicate that the speaker/microphones are not in-use.

Up to two external displays may be connected as the UHD 620 iGPU supports a maximum of three independent displays. The maximum external display resolutions are:

  • 5120 x 2280 @ 60 Hz using one USB-C connector (not quite 5k; Max DisplayPort 1.2 HBR2)
  • 4096 x 2304 @ 60 Hz using both USB-C connectors (2 x 4k monitors)
  • 4096 x 2160 @ 30 Hz using HDMI 1.4a
  • Miracast is not supported.

Upgradeability

  • The M.2 slot NVME PCIe SSD can be upgraded.
  • The WLAN card can be upgraded.
  • The WWAN card can be replaced with one that works under Linux.
  • The WWAN card slot can be used for a second M.2 storage drive.
  • The battery can be replaced.

The single-DIMM RAM module cannot be replaced because it is soldered on.

Keyboard

Some of the keyboard keys work out-of-the-box on Linux:

  • Keyboard backlight adjustment.
  • Wi-Fi/Bluetooth software on/off.

The others are dependent on support from your desktop environment (but they use standard media key codes so most of them should work):

  • Speaker and Microphone volume adjustment and mute.
  • Display backlight brightness adjustment.
  • Second display extend/mirror (You cannot blame Lenovo for this).
  • “Cog”
  • “Keyboard”
  • “Star”
  • “Print Screen Scissors”

My Thoughts

The Good

  • The HiDPI screen is fantastic.
  • The microphone picks up your voice from a considerable distance.
  • Almost all of the hardware works great on Linux.
  • It has great selection of ports.
  • It is incredibly small and lightweight.

The Bad

  • The glossy screen handles reflections poorly compared to a matte screen, and the 1440p HDR screen is only available as a glossy option.
  • The fingerprint reader does not work on Linux (this would be ugly if Linux had any kind of support for this feature.)
  • The speaker audio quality is certainly not “premium”. It is barely acceptable, in particular the bass is lacklustre.
  • The micro SD card reader drains power?

The Ugly

  • The left side USB Type-C port is unusable with the RJ-45 Ethernet adaptor plugged in at the same time because they physically do not fit alongside each other.
  • The WWAN module is not supported by Lenovo on Linux.
    • However, there is a workaround if you get a particular, compatible WWAN chip.
    • In general, I would suggest tethering to your phone.

The Future

In general, while, naturally, I would like improvements to all aspects of the laptop such as the CPU, GPU, RAM, weight, and size, there are some particular improvements that I think are feasible.

I believe the following hardware changes should be implemented on the next the X1 Carbon:

  • The heat vents should be on the back edge of the laptop, rather than on the right side which blows hot air straight on to your mouse hand.
  • There should be at least one USB Type-C port on both sides of the laptop, because this will make it easier to charge the laptop and use other devices depending on where you are.
  • The audio quality of the speakers should be improved with deeper bass, and by moving them to a forward-firing position at the top of the keyboard.
  • A 3:2 aspect ratio screen would remove the large bezel at the bottom, and improve productivity.
  • Improving the display’s refresh rate to at least 120 Hz would improve the general experience.
  • The entire surface of the trackpad should be depressible (to click). Currently it gradually becomes harder as you go up and the top part is not depressible at all. It is painful to use the trackpad in this way.
  • A side-facing SD Card reader would be more usable than the current rear placement.
  • A better iGPU such as Intel’s Iris Pro would be wonderful, particularly as browsers become GPU accelerated.
  • It would be nice if the RAM was dual-slot, user-replaceable, and up to at least 32GB.
  • The arrow keys should be slightly larger and better separated from the rest of the keyboard to make it easier to quickly move your hand to them.
  • There should be a (Linux-compatible) ambient light sensor to automatically adjust the brightness of the screen. The camera could be used for this purpose, but that would defeat the shutter.

It seems that Intel will not be making significant improvements to their 9th Gen processors (they will have pretty much the same IPC and power consumption), so it will be interesting to see what the 7th Gen X1 Carbon is like. At the moment, I do not think it will offer any reason to upgrade.

(2020 April: Even the 8th Gen X1 Carbon offers no significant reason to upgrade. These successor generations have only improved the audio. Lenovo skipped out on the potential iGPU improvements. The new XPS 13 has a 16:10 screen which is wonderful; the ThinkPad is stuck on 16:9.)