- ✓Slim, sub-1kg 12.5-inch ultrabook
- ✓Convertible, via 360-degree 'watchband' hinge
- ✓Tough carbon-fibre chassis
- ✓All-day battery life
- ✕Keyboard lacks responsiveness
- ✕Core M rather than Core i5 or i7 processor
- ✕SSD storage limited to 256GB
- ✕Average-quality audio subsystem
Last year the Lenovo Yoga 900 caught our attention as a high-quality convertible 13.3-inch ultrabook with an innovative 'watchband' hinge mechanism. The 12-inch Yoga 900s retains the watchband hinge and is generally very similar to its predecessor (including starting at the same £999.99 inc. VAT price), but is a smaller, slimmer and even lighter take on the ultrabook format.
The Yoga 900s has a carbon-fibre chassis, which helps to make it a tough and durable laptop. There is some flex in the lid section, but that's to be expected when the whole computer measures just 12.8mm at its thickest point, with the lid comprising around 5mm of that. Lenovo claims the Yoga 900s to be "the thinnest convertible laptop on Planet Earth" (as of November last year, at any rate).
With a footprint of 305mm by 208mm, the 12-inch Yoga 900s will sit comfortably in all but the smallest of travel bags. Lenovo has worked hard to keep this laptop's weight under the magic 1kg mark and has (only just) managed it: the Yoga 900s weighs 999 grams. The 13.3-inch Yoga 900 weighs 1.29kg, by contrast.
The watchband hinge is a defining feature of this ultrabook. As on previous models, this very visual piece of engineering -- comprising 813 individual components -- allows the screen to rotate the screen through 360 degrees, supporting four modes (see above): standard laptop mode; a 'stand' mode with the screen facing outwards and the keyboard laying face down; an A-shaped 'tent' mode; and tablet mode with the screen rotated the full 360 degrees.
This degree of flexibility may appeal, but it's worth noting that the keyboard doesn't lock when the screen is rotated, making it rather vulnerable to rough handling or accidental knocks. That's not unusual, but we've seen examples where the keyboard does lock, and prefer the protection this offers.
As with the Yoga 900, we're sceptical of Lenovo's claim for its Auto Lock system: the hinge is supposedly configured to make it easy to open and close the laptop one-handed. Closing works fine with one hand, but we found that two hands were needed to open the shell.
The Yoga S comes in two colour schemes: Champagne Gold and -- as on our review unit -- Silver. The silver keys picked out against a dark grey surround look a little tacky to us, but obviously this is a matter of taste.
What's certain is that the keyboard must fit into a relatively small chassis, which may make typing a little awkward for those with larger hands. The Enter key and top row of shortcut keys are particularly small, for example. Oddly, the four arrow keys -- which are often reduced in size on laptop keyboards -- are a little larger than average on the Yoga 900s.
The biggest potential issue as far as typing goes, though, is that the keys themselves don't depress very far. We weren't especially troubled by this, but some users may find the keys unresponsive.
The trackpad is perfectly effective, though we found we were more prone to accidentally hit it on this smaller-format device than when using larger laptops. It's easily disabled with a function key if necessary.
The 12-inch IPS touchscreen on the Yoga 900s is quite reflective, and its 2,560-by-1,440-pixel resolution (245ppi) is lower than its 13.3-inch predecessor's 3,200 by 1,800 (276ppi). It's a bit tricky having two document windows open side by side on the smaller screen, but that's a perennial issue with sub-13.3-inch laptops. The Yoga 900s also supports Lenovo's Active Pen stylus, but we weren't able to test this as it wasn't supplied with our review sample.
Because the Yoga 900s is so light, we tended to use tablet mode more, especially for viewing video. Consequently, we were more forgiving of the relatively large screen bezel, which is required so that you don't keep activating the touchscreen accidentally when holding the device in tablet mode.
Our £1,099.99 (inc. VAT) Yoga 900s review sample was powered by a 1.2-3.1GHz Intel Core m7-6Y75 processor with 8GB of RAM -- the entry-level £999.99 (inc. VAT) model runs a 1.1-2.7GHz Core m5-6Y64 with 4GB. This puts the Yoga 900s some way behind the Yoga 900 with its Core i5 and Core i7 processors. Similarly, there's only 256GB of SSD storage (128GB in the entry-level model), whereas the Yoga 900 accommodates up to 512GB.
We found the Yoga 900's audio subsystem rather better than average, but for its successor the word 'average' will suffice.
Ports and connectors are relatively minimal, but do include a full-size USB 3.0 port and a USB Type-C port. The power input also doubles up to provide USB 2.0 connectivity. The only other connector is a 3.5mm headset jack.
Lenovo claims that the 4-cell battery in the Yoga 900s will deliver up to 10.5 hours of video playback from a full charge. Using it for mainstream document creation/editing, web browsing and media consumption, we found that a typical five-hour stint reduced the battery from 96 percent to 40 percent. On that basis, most users should get a day's work out of the Yoga 900s with a bit of battery power to spare.
Lenovo's Yoga 900s offers good battery life, the clever watchband hinge and sub-1kg weight that makes working in tablet mode a practical choice. But there are irritations too -- notably the keyboard, which is a bit too light-touch for our taste.
By adding the 12-inch Core M-based Yoga 900s to its convertible ultrabook stable, Lenovo offers a clear choice: if you value portability and battery life and can live with a lower spec, go with the Yoga 900s; if you value Core i5/i7 CPU power, SSD storage up to 512GB and higher screen resolution, and don't mind lugging a bit more bulk and weight, choose the Yoga 900.
|Operating System||Windows 10 Home 64-bit Edition|
|Processor / Chipset|
|CPU||Intel Core m5 (6th Gen) 6Y54 / 1.1 GHz|
|Max Turbo Speed||2.7 GHz|
|Number of Cores||Dual-Core|
|Features||integrated memory controller|
|Installed Size||4 MB|
|Memory Speed||1600 MHz|
|Memory Specification Compliance||PC3L-12800|
|Configuration Features||provided memory is soldered|
|Installed Size||4 GB|
|Rated Memory Speed||1600 MHz|
|RAM||4 GB (provided memory is soldered)|
|Max Supported Size||4 GB|
|Speed||1600 MHz / PC3L-12800|
|LCD Backlight Technology||LED backlight|
|Resolution||1920 x 1080 (Full HD)|
|Image Aspect Ratio||16:9|
|Touchscreen||yes (10-point multi-touch)|
|Diagonal Size (metric)||31.8 cm|
|Display Resolution Abbreviation||Full HD|
|Audio & Video|
|Graphics Processor||Intel HD Graphics 515|
|Sound||Stereo speakers, two microphones|
|Wireless Protocol||802.11a/b/g/n/ac, Bluetooth 4.0|
|Wireless Controller||Broadcom BCM4350|
|Drive Type||no optical drive|
|CPU Type||Core m5|
|Clock Speed||1.1 GHz|
|Run Time (Up To)||10.5 hour(s)|
|Input||AC 120/230 V (50/60 Hz)|
|Output||40 Watt, 20 V, 2 A|
|Connections & Expansion|
Headphone/microphone combo jack
|Product Line||Lenovo Yoga 900S-12ISK|
|Notebook Type||2-in-1, thin and light|
|Mechanical Design||360° flip design|
|Hard Drive Capacity||128 GB|
|Diagonal Size||12.5 in|
|Data Link Protocol||Bluetooth 4.0, IEEE 802.11a, IEEE 802.11ac, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n|
|Wireless NIC||Broadcom BCM4350|
|Features||1 USB 2.0 (DC-In combo), 1 USB 3.0 with Video-out|
|Included Accessories||power adapter|
|Dimensions & Weight|
|Compliant Standards||Dolby Audio Premium|
|Type||1 year warranty|
|Operating System / Software|
|OS Provided: Type||Windows 10 Home 64-bit Edition|
|Graphics Processor||Intel HD Graphics 515|
|Graphics Processor Series||Intel HD Graphics|
|Service & Support|
|Type||1 year warranty|
|Service & Support Details|
|Location||pick-up and return|
|Full Contract Period||1 year|