To replace my dead laptop, I just bought a Lenovo IdeaPad Yoga 13, often identified with the code 59384174 although the official model number seems to be 2191; the EAN13 code is 0887942530297. Here are my impressions about the device. I am using Debian Testing amd64, kernel version is 3.13.1-amd64 as of this writing.

Criteria

I wanted a laptop with at least 13 inches (feels too cramped otherwise), with an SSD (and no SSD/HDD hybrid, I dislike mechanical drives for laptops and would not trust the controller's caching policy), with a screen resolution better than the default WXGA 1366 by 768 resolution of cheap 13 inch laptop screens, and I wanted the device to be light and slim (the Yoga 13 is 17 mm thick and weighs 1.5 kgs). Oh, and I wanted reasonable battery life.

Windows refund

The machine came with a preinstalled Windows 8. I contacted Lenovo France to get it refunded. However, the only option that their customer service offer to get a Windows refund is to refund the entire laptop... this is really sad.

Price

I managed to buy the device for 590 euros: it was priced at 700 euros by Cdiscount (may not apply anymore as of this writing), 10 euros could be recouped if paying via Buyster, and 100 euros could be recouped from Lenovo France as of this writing through a special offer. From all the devices that I reviewed, this was the cheapest one to satisfy all my criteria, by a fairly large margin.

Charger

The charger is pleasantly slim and outputs 20V. The plug for the power slot in the device is a rectangular but reversible plug.

Power button

Note that if you need to power down the device during the Windows setup phase (because, say, you inadvertently entered it), long-pressing the power button will suspend the computer, not power it off. You need to continue pressing the button after that to turn the computer down. Also note that the power button is easy to hit by mistake, hence I configured it in /etc/systemd/logind.conf to not cause any event when pressed; you still have to be careful when the device is suspended so that you do not make it resume by mistake, e.g., when putting it in a bag (because of the risk of overheating).

Screen

The screen looks very nice, though a bit glossy. The 1600 by 900 resolution is pleasant. The viewing angle is very wide (no noticeable hue shift except when you start looking at it diagonally). Screen backlighting can be controlled (even disabled outright) through /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight/brightness. By default there is some tearing during video playback, I tried to fix it with this method, not sure how much it helps.

Tablet

The main selling point of the Yoga series is that the screen folds 360 degrees to a tablet-like configuration. I only wanted to buy a laptop and have little plans to use this functionality (also for the reason that I wouldn't know which operating system to use to work as a tablet yet give me a suitable environment for a regular laptop), so that's just a bonus. Trying out the mechanism out of curiosity, it makes a fairly heavy and strange tablet, and having the keyboard behind is fairly bizarre. The rotation is achieved by a double-hinge mechanism: a standard hinge system works up to 180 degrees, and then those hinges rotate in a second hinge to go all the way to 360. The mechanism doesn't look especially solid and I wouldn't trust it not to break if used regularly, however for less than 180 degrees the standard hinge mechanism seems OK... After a few months of use, the right hinge has become a bit loose compared to the left one, which worries me a bit. A related complaint is that some magnets are used to make the 0 degrees (closed lid) and 360 degrees (tablet configuration) stable, and for 0 degrees those magnets are a bit too strong, so that it is a bit hard to open the laptop. On Linux, of course, if you use the Yoga in trestle mode, almost fully folded and reversed, which can be convenient e.g. to watch movies without having the keyboard in the way, you will have to take care of reversing the display with xrandr but also of reversing the input if you want to use the touchscreen. Here's a script to do this for you.

Orientation sensor

From the existence of a hardware button to lock screen rotation (see below), I imagine that the device must include an accelerometer, but it doesn't seem to be supported by the Linux kernel. Nothing relevant shows up in /proc/bus/input/devices or in /dev/input. In any case it appears that the mechanism is causing problems, which I have also experienced, and I had to add the relevant commands to /etc/rc.local to make it stop.

Sound

Interestingly, speakers are on the rear and the integrated microphone is on the side, probably because they must be usable both in laptop and tablet configuration. Sound quality is not especially good but not especially bad either, given the form factor.

Connectivity

The device features one minijack port (combined microphone and headphones), one eSATA-USB hybrid port, one USB port, one HDMI port, the power supply connector, one USB port, one SDcard-MMC reader, and that's it. Of course, no Ethernet port because the device is too thin. I bought a cheap USB-Ethernet adapter which was detected out of the box by Linux and works fine except that it is USB 1.0 so it is limited to about 750 kB/s.

Keyboard

The keyboard is pleasant enough, the keys are fairly high and have a reasonable size. The Left control is at the bottom left of the keyboard with the Fn button is at its right, which is how it should be (some laptops have the reverse). There is only a Super_L modifier (Windows key), not Super_R, but that's OK. Keys are positioned reasonably except that PageUp and PageDown are not quite at the position where I would have expected them (I would have expected them to be one row higher). By default, the F1-F12 keys can only be reached with Fn and the special (Volume, etc) fonctionalities being the default, but fortunately this can be changed in BIOS. The F1-F12 keys have the following additional features:

1. Mute, generating XF86AudioMute.
2. Volume down, generating XF86AudioLowerVolume.
3. Volume up, generating XF86AudioRaiseVolume.
4. Cross key, generating an Alt-F4 sequence (Windows keyboard shortcut to close a window).
5. Refresh key, generating F5 (so doubles with the default behavior of the key.
6. Disable touchpad key, exposes no events in xev but reports the following in dmesg: atkbd serio0: Unknown key pressed (translated set 2, code 0xbe on isa0060/serio0). Use 'setkeycodes e03e <keycode>' to make it known.
7. Plane mode key, generating XF86WLAN, and from the dmesg it seems like the Wifi driver is seeing this also and disassociates, but nothing seems to be seen in rfkill.
8. Three rectangles key, generating a Ctrl_L-Alt_L-Tab sequence (probably a Windows keyboard shortcut to switch application or something).
9. Screen off key, toggles backlighting on and off (preempts the status in intel_backlight, no xev or dmesg event).
10. Screen whatever key, generates a Super_L press? (Nothing more shows up, maybe things would be different if I had an external screen plugged in, but I have none to test this hypothesis).
11. Brightness down key, generates XF86MonBrightnessDown (my i3 config uses xbacklight to handle this)
12. Brightness up key, generates XF86MonBrightnessUp (ditto)

Additional keys

The laptop comes with a bunch of strange additional buttons, in addition to the keyboard. There is a button with a Windows logo (annoying, that) below the screen, which must be intended to be used in tablet mode with Windows; from xev it seems to simulate a press on Super_L (the windows key on keyboards), but only when released (it generates both the KeyPress and KeyRelease events when released). On the left side are two volume keys generating XF86AudioLowerVolume and XF86AudioRaiseVolume. On the right side is a button to lock screen rotation, which seems to emit the sequence Super_L+o (the Windows hotkey to do this, it seems). Last comes the power button and a small button on the left that can only be pressed with a pen or such; the documentation refers to it as the Novo button. It generates XF86Launch2.

Secure boot

Secure boot can be disabled in BIOS, whatever that is. BIOS offers both UEFI and legacy BIOS boot, legacy boot is not too fast. Interestingly trying to boot a Debian install USB key with UEFI will work except that the screen display will be garbled, this is fixed using legacy boot.

Bluetooth

To get Bluetooth to work, install the driver and load the module. Note that it seems to be necessary to manually install the Bluetooth driver even though the Wifi driver is now integrated to the kernel. Now, here is how I get my Bose Mini SoundLink speakers to work. bluez-test-audio seems to have disappeared from the bluez package in Debian recently, I am not sure about how to fix these instructions. First, reset those speakers and put them in discoverable mode. Install the bluetooth daemon (Debian package blueetoth) and pulseaudio-module-bluetooth, try to issue pactl load-module module-bluetooth-discover. Ensure in rfkill that the hci0 device exists and isn't blocked. Then, retrieve their address by issuing sudo hcitool scan. Issue bluez-simple-agent hci0 ADDRESS and then bluez-test-audio connect ADDRESS. The speakers should indicate that pairing succeded. Now, check in pacmd list-sinks that a sink exists for the speakers, and use pavuctl to connect your music player to the right sink.

SD card reader

The reader appears as /dev/sdb, not /dev/mmcblk*, and inserting a card will not do anything until you try accessing it with fdisk -l /dev/sdb, at which point the partition files /dev/sdb* should be created. I haven't tried if booting off the SD card reader was possible.

Touchpad

Since I wrote these instructions, things seem to have improved, so I am not using mtrack anymore. The following should no longer apply. The touchpad has an anti-feature: the button press zones are tactile, meaning that, by default, your pointer will move when trying to just click, this is extremely annoying. You can use synclient to set AreaBottomEdge when using the synaptics driver, but this has another downside: it means you cannot click and drag because clicking locks the pointer. I got much better results by installing xserver-xorg-input-mtrack and enabling it in xorg.conf: clicking at the bottom locks the mouse pointer except past a certain move threshold, which is the right thing to do. It is fairly annoying, however, that I couldn't get mtrack's ButtonZonesEnable feature to work, so to do a right click I have to click with one other finger touching the pad (and when left-clicking I mustn't leave another finger on the pad). I tend to touch the pad while typing, the IgnorePalm option seems to help a bit to ignore that.

Webcam

Webcam works. Test it, e.g., with Cheese.

Ambient light sensor

The device has an ambient light sensor on the screen that can be made to work with the Zenbook driver (clone, make, insmod als.ko, requires linux-headers etc.); the value ranges from 0 in total darkness to 40000 in maximum light, with a value in the 1500-2000 range in normal indoor lighting conditions. I didn't try to write a script to adjust screen brightness automatically based on ambient light.

CPU and memory

/proc/meminfo reports 3938992 kB RAM. I haven't checked but there should be one RAM slot with non-soldered RAM, upgradeable by replacing by an 8 GB DDR3 module in SO-DIMM 204 pins packaging (costing about 75 euros as of this writing). /proc/cpuinfo reports the CPU as a Intel(R) Core(TM) i3-3227U CPU @ 1.90GHz. CPU frequency scaling is available, but cpufreq-info reports that it uses the intel_pstate driver, and that only the performance and powersave governors are available, with powersave being used by default. Loading the performance driver doesn't seem to make much of a difference. From cpufreq-aperf it looks like the CPU frequency increases up to the maximum 1.9 Ghz under load, even with the powersave governor (so it isn't locking the frequency to the lowest possible value).

Battery

Battery status can be read with ACPI as expected. From a quick test, during reasonable usage (browsing, investigating hotkeys, partitioning, etc.), and with phone plugged in (to tether and work around a Wifi glitch), battery life was around 4:30.

Screws

The entire case is closed with Torx-looking screws, and it seems that nothing is intended to be user-serviceable. In particular, you are probably not expected to replace the battery yourself. Of course, people have succeeded in opening their device, and a cursory search suggests that replacement batteries may still be available.

Fan and temperature

Two fans evacuate heat at the back of the unit. Four temperature sensors are detected by libsensors, one under acpitz-virtual-0 and two under coretemp-isa-0000. Temperatures are about 40 degrees in standard usage, with the fans spinning. Annoyingly I found no way to retrieve the fan RPM or to control the fans, and I find it sad that the fans seem to be always spinning even when temperature is low; they are not too noisy but total silence would be perfect, and that's just wasteful in terms of battery life. Temperatures reach 50 degrees and the fans speed up a bit under heavy load. There is code to control fan speed in software, that works fine. I recommend it heartily, because under normal loads the CPU temperature will stay well below 55 degrees with the fans powered down entirely.After trying to run with this script for a while, I no longer use it, because when the script is running it semes that the kernel occasionally sees critical temperature values and powers down. As those values are outliers I think they are just a glitch, but it seems that running the script triggers it, I don't understand why.

SSD

SSD is a Samsung MZMTD256, 238.47 GiB. Surprisingly it seems that if you are willing to open up your unit you can install a second mSATA SSD in a vacant slot. The default partition layout is surreal, with a whopping 7 partitions: WINRE_DRV, a 1000 MiB NTFS partition, SYSTEM_DRRRV, a 260 MiB bootable FAT32 partition, LRS_ESP, a 1000 MiB FAT32 partition, a 128 MiB msftres unknown partition, the main Windows partition (which is the only one that isn't hidden), and from memory a 4 GB partition and a 12 GB partition for obscure recovery purposes. I didn't touch the first four ones because they don't take up that much space and I'm afraid of making the device unbootable (that's probably an unrealistic fear, but who knows...), but I removed the Windows partition and the two last recovery partitions to install Debian instead. No problems in using GRUB (though I haven't tried booting anything except Debian).

Network

Wifi does not work out of the box, and the absence of an Ethernet port means that Debian installation may be painful. A possible workaround is to use an USB-Ethernet adapter (not tested), or to tether a mobile phone's Wifi connection (Debian install knows how to use such connections) The Wifi chip has USB ID 0bda:1724, and to make it work, for now, you should compile and install the rtl8723au driver. It is painless and works. However, it doesn't seem like changing the MAC address is supported; sudo ifconfig wlan0 hw ether whatever doesn't fail but doesn't change anything, even if the interface is down and even if it is rfkilled. I haven't tried very hard yet or investigated whether the driver had a specific option for this. It does not look like activating monitor mode for airodump-ng works either. Also, the driver was merged in Linux 3.15, so with sufficiently recent kernels the Wifi now works out of the box. Sadly, there seem to be some crashes related to the Wifi, see this bug. Fortunately, these crashes can be avoided by installing manually the rtl8723au driver instead of using the one shipped by the kernel.

Hibernate

pm-suspend seems to work, taking about 1 second to suspend and resume. pm-hibernate works but I had to configure the hibernate swap partition manually. Hibernating takes around 10 seconds, booting and resuming from hibernate takes about 16 seconds.

All in all, I am pretty satisfied with the device so far.