Lenovo Yoga 900S 12ISK Convertible Review

The Yoga 900 series consists of flagship models in contrast to the mainstream Yoga 700 and 500 series. Thus, the 900S does not disappoint visually as it still carries the same look and feel as the 900 including the smooth and rounded matte outer surfaces, carbon fiber chassis, rubberized palm rests, edges, and corners, and wristband hinge that is exclusive to high-end Yoga SKUs. A minor complaint is that there is no notch on the front for a good grip, so opening the lid can be difficult even with two hands. Otherwise, we're relieved to see that Lenovo did not taken any design shortcuts just because the system is smaller and less powerful than the proper Yoga 900. It may be the size of a netbook, but it certainly feels much better than one.

There is also not much to complain regarding workmanship and build quality. We can notice no unintended gaps on our test unit and the lid itself is resistant to major twisting and depression. Pushing down on the center of the keyboard will depress it slightly, but the base is otherwise firm all around. Perhaps more importantly, the hinges feel strong and consistent up to its maximum angle for easy switching between modes.

Maintenance

We weren't expecting serviceability to be so easy on the 900S especially when considering its size class and highly integrated components. Nonetheless, a T05 Torx wrench is all that is required to safely remove the bottom panel and to expose the large battery, WLAN module, M.2 2280 SSD, and copper heat plate over the processor and memory modules. RAM is fixed so there are no expandability options here.

Warranty

The standard one-year warranty applies to all new purchases. As usual from Lenovo, the manufacturer offers a wide range of warranty options including up to 3 years of onsite service and accidental damage protection for an additional $179.

Keyboard

The Chiclet keyboard (25.5 x 9.5 cm) provides two levels of White backlight lighting and the Gold-colored keys visually match the hinge and outer lid of the notebook. This is also where many users may find the Yoga 900S unlikable as the keys have very shallow travel even for a thin notebook. As shown in the picture below, the keyboard keys are already nearly on the same plane as the surrounding surface. Feedback suffers as a result and the Space bar in particular feels softer than usual when pressed. It may take some time for new users to become accustomed to the feel of the keyboard and, unlike on certain Yoga models, there is no Lift 'n Lock feature for the Yoga 900S.

On the flip side, typing is quiet and almost clatter-free due to the soft feedback and shallow travel. The Directional keys are also large and easier to use than on some 15-inch notebooks where they can feel squeezed between the QWERTY and NumPad keys. A volume rocker would have been a useful addition on the side of the device.

Touchpad

The touchpad (9.25 x 6.25 cm) is smooth to the touch and adequately sized for a 12-inch convertible. Its dark gray plastic surface, however, attracts fingerprints quite easily whereas the Gold keyboard keys do a much better job at hiding them.

Basic cursor control works reliably on the touchpad and the Synaptics software is able to recognize up to four fingers simultaneously. Multi-touch gestures are a little difficult, however, as even pinch-to-zoom is hit or miss and will not always register. Meanwhile, the integrated mouse keys have a firm auditory click from the shallow travel and are easy to press for comfortable use. Users may find that using the touchscreen itself can be more responsive and ergonomic than the touchpad for some inputs.

Color coverage is measured to be 64 percent of the sRGB standard, which is typical for a mainstream IPS panel. This is comparable to the Yoga 260, but well below that of the Spectre and XPS 13 where their panels target the full sRGB spectrum for deeper and more accurate colors. In fact, the gamut of the 900S is only about 66 percent of the display found on the Spectre. Fortunately, the more limited color space means little to the target audience of the 900S as the convertible is not designed for professional digital artists or editing applications where accurate colors are required.

Further measurements with an X-Rite spectrophotometer reveal accurate grayscale and good RGB balance. A quick calibration has very little effect on the final picture, so users shouldn't need to worry about having to calibrate their panels out-of-the-box. Colors are generally accurate as well, but will still grow more inaccurate the higher the saturation level due to the panel's limited sRGB coverage.

Outdoor usability is average despite the bright backlight because of the very glossy panel. Reflections and glare are essentially inevitable if working outdoors. The 360-degree hinge comes in handy here to reduce as much glare as possible, but the screen will still wash out if under direct sunlight.

Viewing angles are otherwise excellent from the IPS panel which is crucial for a Yoga convertible. Colors and contrast do not shift dramatically if viewing on landscape or portrait. Apparent contrast still decreases if not viewing directly at the screen, but this is a common characteristic of IPS displays.

The Core m5-6Y54 in our 900S performs slower than the average Core m5-6Y54 in our database according to CineBench benchmarks. We compared our results to the Lenovo Ideapad Miix 700 that carries the exact same processor, but scores on the Miix are significantly higher especially in single-threaded benchmarks. The low scores can be explained by the Turbo Boost throttling behavior of the 900S as detailed in the Stress Test section below.

Raw processor performance is still significantly better than an Atom Z8300 on very low-cost netbooks and tablets despite the poor Core m5-6Y54 performance from the 900S. See our dedicated CPU page on the processor for additional technical details and comparisons.

PCMark 8 ranks our Lenovo in the same ballpark as the Apple MacBook 12. Systems with ULV processors score are about 20 to 30 percent higher including the ThinkPad T450s and Spectre. The limited processing power of the Core m5 puts the 900S at a disadvantage even against some popular tablets.

We experienced no notable software or hardware issues during our time with the Lenovo convertible.

Raw graphics performance from the integrated HD Graphics 515 is again below what we were expecting. We compared our results to the HP EliteBook G1 with the same Core m5-6Y54 CPU and HD 515 GPU only to see that the HP can score at least 50 percent higher than the Lenovo in 3DMark benchmarks. We reran the tests to confirm and the final scores were not significantly any different. Overall graphics performance from the 900S is 20 to 30 percent below that of the HD 4400 as found on older Haswell processors.

See our dedicated GPU page on the HD Graphics 515 for more technical details and benchmark comparisons.

The below average benchmark results from the 900S makes sense after closer analyses with Prime95 and FurMark. The system quickly and easily throttles when subjected to extreme loads. According to our observations, the 900S will cycle its CPU and GPU clock rates to maintain a mid 50 C operating range and to prevent core temperatures from reaching anything higher than 70 C. Running Prime95 will cycle the CPU from 1.1 GHz to 1.6 GHz compared to the processor's maximum rated Turbo Boost of 2.4 GHz for multi-threaded workloads. The integrated GPU behaves similarly and both CPU and GPU clock rates will throttle even further when running both Prime95 and FurMark simultaneously.

Unigine Valley is more representative of gaming loads than the above mentioned benchmarks. Nonetheless, the system still throttles as it struggles to maintain consistent clock rates. The GPU itself is rated for a maximum Turbo clock rate of 1000 MHz and it can barely maintain 600 MHz here on the Lenovo.

Running on battery power will not throttle the system any further. A 3DMark 11 run on batteries returns Graphics and Physics scores of 858 and 2256 points, respectively, compared to 803 and 2333 points when connected to mains.

The non-removable 53 Wh battery is quite large for a notebook this size. Combine this with the low-power Core M CPU and fan-less design and you have a very long-lasting system. We clocked in almost 10 hours of constant WLAN use at a brightness setting of 150 nits (75 percent setting), which is very good for a convertible. Lenovo advertises a runtime of 10.5 hours, so our own tests come quite close. In comparison, the MacBook 12 and XPS 13 lasted for one to two hours shorter under similar WLAN conditions. Users can still expect at least 3.5 hours of heavy use and on maximum display brightness.

Recharging from near zero to full capacity will take roughly 2 to 2.5 hours.