Lenovo ThinkPad X240 Full HD Notebook Review

Because of the increased resolution from 1366x768 to 1920x1080 pixels (with the same diagonal size of 12.5 inches), the pixel density makes a big jump as well. Instead of 125, the display now has an impressive 176 ppi, which results in a very sharp presentation even with small viewing distances. The space on the desktop is increased at the same time: Even some multitasking is possible if you waive an adjustment of the scaling option to increase the size of symbols and fonts – this is hardly possible with the WXGA version. 

Even though our review unit cannot manage the advertised maximum brightness (400 cd/m²), the measured result of 348 cd/m² is still impressive nonetheless. The small deficit compared to the Dell Latitude E7240 (Full HD Touch: 389 cd/m², WXGA version only 211 cd/m²) is acceptable; HP's EliteBook 820 G1 (211 cd/m²) on the other hand does not stand a chance. You can adjust the brightness with 15 steps all the way down to 5 cd/m² in dark environments.

Subjectively, the brightness distribution is very even over the whole display surface, we can only see a slight case of screen bleeding under certain circumstances (black background, no ambient light, maximum luminance). However, this is hardly annoying in practice, and we can only speak for our specific review unit; there are usually somewhat large deviations in regard to the brightness distribution.

Our review unit can confirm the excellent viewing angle stability of the previously reviewed WXGA version without any restrictions. That is not really a surprise since both configurations use – as we already mentioned – a very similar IPS panel apart from the resolution. Especially viewing angles from below or from the sides do not change the picture at all. Views from above on the other hand can result in slight reflections, but they are hardly noticeable in practice.

Similar to our last review, the X240 once again uses the Core i7-4600U, which is currently Intel's fastest processor with a TDP of 15 Watts. The frugal dual-core supports Hyperthreading and runs at 2.1 GHz, but can be overclocked up to 3.3 GHz (2 cores: 2.9 GHz) via Turbo Boost. Just like any Haswell processor, the i7-4600U is manufactured in a 22 nm process with FinFETs (3D transistors).

Graphics are handled by the integrated HD Graphics 4400 that runs from 200 up to 1,100 MHz. Dedicated alternatives from AMD or Nvidia are not available for the Lenovo, HP or Dell – but that is not really an issue for a business notebook.

A drawback on the other hand is the decision of the manufacturer to use just one memory slot. This does not only limit the maximum amount of memory to the 8 GB of our review unit, but also the (GPU) performance because of the resulting single-channel memory interface. Files can be stored on a 256 GB SSD.

Even though terms like energy-efficient or ULV model do not create high expectations for the performance, the Core i7-4600U actually offers impressive performance reserves. Single thread benchmarks in particular benefit from the high clocks between 3.2-3.3 GHz, the excellent results can keep up with some much more energy-hungry mainstream CPUs.

The X240 falls slightly behind the EliteBook 820 G1 with the identical components in multithread tests. The ThinkPad can utilize its maximum Turbo potential at first, but the clock drops to 2.3-2.4 GHz after a couple of seconds. It seems that we got a pretty "bad" CPU with a high power dissipation that reaches its TDP limit of 15 Watts with this clock – we could determine around 2.5-2.6 GHz for other i7-4600 CPUs under the same circumstances. However, the difference is not really perceptible and the clock is not reduced on battery power, either.

Despite the limited space, the X240 uses a standard 2.5-inch SSD from Samsung (MZ7TD256HAFV). Compared to the Intel SSD Pro 1500 of the EliteBook 820 G1, the drive manages a small advantage in almost every benchmark; only the 4K write performance (4K-64) is slightly behind the rival. The top spot, however, is secured by the Dell Latitude E7240: The Samsung SM841 manages the highest transfer rates, despite the smallest capacity.

Depending on the benchmark, the single-channel interface can limit the 3D performance of the HD Graphics 4400 by around 10 to 30 percent, which can really make a difference on such a low performance level. Even older GPUs like a GeForce GT 720M can beat the processor graphics by more than 50 percent as a result. An additional GPU would increase the power consumption, so users will have to live with it.

Apart from demanding 3D applications, for example, complex CAD projects, the HD 4400 serves its purpose: Multimedia tasks like video acceleration (even in 4K resolution) are handled without problems, and you get a very efficient hardware encoder/transcoder with Quick Sync.

While the case does not even get lukewarm during idle, we can see surface temperatures above 40 °C (104 °F) at some spots during our stress test (Prime95 + FurMark). Fortunately, the high values are limited to the area around the fan exhaust (at the left back of the case). The palm rest on the other hand stays comparatively cool, so the user can continue the work without any restrictions.

The CPU only warms up to 69 °C (156.2 °F; core temperature) with the activated Turbo Boost+; we can measure around 10 °C (~18 °F) more when we waive the rpm increase. Both results are uncritical since Intel specifies the maximum temperature of the Core i7-4600U up to 100 °C (212 °F). The sometimes comparatively low clocks of the processor (1.0 GHz) and the graphics card (700 MHz) are once again a result of the TDP limitation.

The weak stereo speakers of the X240 are hardly suited for larger rooms. Even the maximum volume of the speakers does not result in more than a meager 76 dB(A), a low value, even for a business notebook. There is also room for improvement in terms of quality: Frequencies below 250 Hz are basically not available, so the sound experience is very tinny and focused on high tones. At least you can attach an external sound system via the stereo jack.

Let us start our verdict with the important question: Is the Full HD display worth the additional charge of almost 100 Euros (~$136) or not? For everyone who often uses large Excel sheets on the road and many applications simultaneously, the clear answer is "Yes". Only the higher resolution transforms the small subnotebook into a full mobile workplace.

At the same time, we want to mention that the display does not offer any additional features apart from the higher resolution. Stable viewing angles and a powerful background illumination are also offered by the less expensive WXGA IPS version, but both panels cannot convince us in terms of colors. We would only have hoped for better performance.

Still, the X240 is one of the best subnotebooks of its class, and we do not want to get into the details of highlights like the excellent keyboard or the low emissions once again. Unfortunately, this quality comes at a price, regardless of the selected display – even an average configuration easily costs more than 1,000 Euros (~$1356). However, the situation is not different with devices from HP or Dell, so we can give the deserved purchase recommendation for the Lenovo X240.