Lenovo ThinkPad X1 Carbon 2016 (Core i7, WQHD) Ultrabook Review

After Lenovo has shrunk the T460s to about the size of the ThinkPad X1 from 2015, the manufacturer also had to make the new Carbon slimmer. With a height of about 16,5 mm and a weight of just under 1.2 kg, our test model is about 2 mm slimmer and 150 g lighter than its in-house competitor. So far, no other 14 inch notebook has ever been that mobile. In direct comparison, this difference is actually noticeable and it is without doubt the main reason to buy the more expensive X1. However, you should consider that the T460s is already thin and light enough to easily carry it in the hand luggage or use it on your lap.

Design, material, and haptics also are quite similar to the recently reviewed T400 series. As the chassis is made from magnesium and carbon fiber reinforced plastics, it is not only very resistant against dirt and smaller scratches, but also withstands twists and depressions without problems. Even the lid does not warp too much, when force is applied. However, a slight flexibility could not be avoided in view of the extremely thin build. Stiff hinges means that it takes two hands to open the Carbon to avoid lifting the base unit. Unfortunately, the hinges to not work as precisely as in other ThinkPads and wobble for a short time whenever you touch the display.

For a price above 1500 Euros, customers may expect flawless build quality. We can confirm that at least our test model of the ThinkPad X1 meets this expectation. Nothing clatters, all parts of the case are flush and all edges have been carefully deburred - quite unlike in our test model of the predecessor.

As expected, the ThinkPad X1 also houses Intel's current Wireless-AC 8260 adapter, which supports WLAN standards 802.11a/b/g/n/ac (2x2, max. 866 Mbit/s) as well as Bluetooth 4.2. With a net transfer rate of about 50 MB/s (TP-Link Archer C7, 3 meters distance, line of sight), the Carbon cannot completely keep up with the impressive 70 MB/s of the T460s with the same module, but it still achieves a decent result. During our test, we could not complain about range and connection stability. On top of that, our test model has a WWAN card from Sierra Wireless on board, which ensures fast internet connection via UMTS, HSPA+, and LTE Cat. 6 on the move.

As so often, the webcam above the display only features a resolution of 1280 x 720 pixels and the recordings are accordingly blurry. Moreover, images suffers from quite faint colors and visible noise (especially in low light scenarios), but almost all competitors show similar weaknesses. In contrast, we want to explicitly praise the high-end array microphone with excellent speech quality, which is typical for ThinkPads.

Security

Except for the Smartcard reader, the X1 Carbon provides all security features you might expect from a modern business notebook including an extremely fast fingerprint reader mit touch sensor, TPM TCG 1.2, a Kensington Lock, and optional passwords for booting, hard drive and BIOS. Attention: vPro is only supported by models with Core i5-6300U or Core i7-6600U, whereas the Core i5-6200U and the Core i7-6500U lack these feature - and so does our test model.

Accessories

Apart from the already mentioned network adapter for the OneLink+ port, the manufacturer only includes a quite big 65 Watt adapter and the obligatory quick guide. In addition, some software is included, which is fortunately largely limited to useful hardware monitoring and management tools.

Maintenance

For opening the device, first remove several screws on the underside, in order to get off the complete underside. The latter is also fixed by several clips, which can be loosened without notable force or tools. The possible maintenance options include cleaning of fans and heatsink as well as replacing the WLAN module, the LTE adapter, and the M.2-2280-SSD; In case of a defect, the screwed battery can be replaced, too. All other components like CPU and RAM are soldered and cannot be upgraded.

Warranty

Lenovo grants a 3 years warranty with on-site service for its higher priced models - which certainly also include the X1 Carbon - from purchase. For about 80 Euros you can expand it to 4 years and for double the price to 5 years. Additional services and accidental damage protection are significantly more expensive.

Just like the ThinkPad T460s, the new X1 is also optionally available with a FullHD (1920 x 1080 pixel, 157 PPI) or a WQHD panel (2560 x 1440 pixels, 210 PPI). Both displays are based on the high-end IPS technology and touted by the manufacturer with a maximum brightness of 300 cd/m² and a contrast ratio of 700:1. However, the data sheet does not list a touchscreen option - such will not be available for the fourth generation of the Carbon for now.

Unfortunately, we have to criticize Lenovo once again for not meeting all promised specifications. Instead of 300 cd/m² we measured only 268 cd/m² in our WQHD model, which is significantly lower than its HP EliteBook Folio 1040 G3 rival's. Another con is PWM control of the backlight (220 Hz, all brightness levels <100 %), which can be perceived as slight flickering by sensitive users. However, we could subjectively not detect limitations in practice.

Typical for IPS displays, the viewing angles are very wide. Even at extreme viewing angles, we could only observe a slight brightness and contrast decrease, yet not extreme color or gamma shifts as in a cheap TN panel. As a result, the user does not need to permanently adapt the opening angle depending on the sitting position. Furthermore, several users can look at the display at the same time.

In the refreshed X1 Carbon the Broadwell processors of the predecessor have been replaced by Intel's newer Skylake processors, which promise higher performance and longer battery runtimes at the same TDP of 15 Watt. You can select between several models from the Core i5-6200U (2.3 - 2.8 GHz) up to the Core i7-6600U (2.6 - 3.4 GHz), which we have already scrutinized in the T460s. Our test model comes with a Core i7-6500U dual core processor with Hyperthreading clocked at up to 2.5 to 3.1 GHz (2 Core Turbo: 3.0 GHz). Attention: Other than the i5-6300U or i7-6600U, the i7-6500U does not support vPro - in case this is required in your company.

As expected, the ThinkPad does not use dedicated graphics solutions, but the integrated HD Graphics 520. As so-called GT2 tier, the Skylake GPU features 24 EUs (also called shader cluster or execution units) and only very limited performance reserves. However, it shines with many modern features like DirectX 12 or hardware accelerated H.265 playback.

Depending on the configuration, Lenovo incorporates 4, 8 or 16 GB of soldered LPDDR3-1866 RAM (dual channel), which can not be upgraded, since a DIMM slot is lacking. While Skylake would also support DDR4-2133, the low power consumption of LDDR3 RAM, which has also been designed for smartphones, might have been the decisive factor here. All models use M.2 SSDs as storage device. Our test model comes with a 256 GB model.

Despite modern 14 nm process, the fastest ULV models of the Skylake generation are limited by their low TDP classification. As a result, several models cannot fully use their Turbo Boost potential under high load. Thus, Lenovo has increased the TDP from 15 to 25 Watt in the T460s, which was not possible in the even slimmer X1 Carbon (probably due to thermal reasons).

If only a single core is used, this does not have an impact and the i7-6500U clocks constantly at the maximum of 3.1 GHz. This changes as soon as a program uses all cores or threads, respectively: Initially, the clock rate is 3.0 GHz, but it falls slightly to 2.8 GHz after Cinebench R15 has been running for about half a minute. Thus, the higher price for fast i7 models only pay off to some extent. Price-conscious buyers should better choose a Core i5-6200U or i5-6300U. We could not detect performance differences in mains operation and on battery during our test.

The incorporated Samsung PM871 (MZNLN256HCHP) a mid-range M.2-2280 SSD with 256 GB TLC-NAND connected to the system via SATA interface. Our benchmarks attest the storage device sequential transfer rates of just under 500 MB/s in reading and 300 MB/s in writing. This is a decent result, although the PM851 predecessor was only insignificantly slower overall. The results in the 4K and 4K-64 tests are good, too.

If highest possible transfer rates are important to you, you should consider the optionally offered PCIe SSDs. Lenovo might probably use the same drives as in the T460s sibling here. Currently, its Samsung SM951a belongs to the fastest SSDs on the market.

Probably also due to the extremely slim design of the X1 Carbon, it is only available with the integrated HD Graphics 520, which accesses the soldered LPDDR3-1866 RAM via a dual channel interface. It is interesting that the slightly smaller bandwidth than the DDR4 interface's in our devices does apparently not have the slightest impact on performance. In the 3DMark 2013 Fire Strike test, our test model even achieved the highest score we have measured for a HD 520 so far. Nevertheless, it is a pity that Lenovo does once again - other than for example Microsoft in the Surface Pro 4 – not offer a configuration with Iris Graphics 540 GPU. Thanks to double the ALUs and dedicated eDRAM VRAM, such models would achieve about 50 to 80 percent higher graphics performance at similar power consumption.

The HD Graphics performs flawlessly when it comes to efficient playback of high resolution videos. The X1 runs our 4K trailer of "Big Buck Bunny" (60 fps, H.265/HEVC) at a CPU load of only 2 percent and idle clock rates.

Thanks to an SSD and almost always still standing fan, the X1 Carbon is not only silent while idle, but also during simple everyday tasks. However, the fan starts running notably quicker than the bigger ThinkPad T460s's under medium load, which is undoubtedly due to the even thinner case. Since you can already hardly hear the fan in a few centimeters distance, this is not disturbing in practice.

When the demand on processor and graphics chip is higher, the noise level climbs to between 36 (3DMark06) and 38 dB(A) (stress test). Together with the subjectively pleasant und uniform frequency characteristics, it is not annoying in the long run.

The temperature management of Lenovo's business notebooks is surprisingly good while idle as well as under load. Even during the stress test, the temperature only exceeds 40 C in two spots. Otherwise, the ThinkPad does not even get lukewarm. Thus, it is possible to use the laptop on the lap without limitations.

The core temperature of the Core i7 remains uncritical at 70 to 75 C, even when Prime95 and FurMark are running simultaneously. That processor and graphics core still only clock at 1300 and 800 MHz, respectively, is caused by reaching the TDP limit of 15 Watt. Thanks to a limit of 25 Watt, the T460s can keep significantly higher frequencies.

With a maximum volume of about 80 dB(A), the down-faced stereo speakers of the X1 Carbon are conveniently loud, but do not sound convincing. The frequency characteristic already falls much at below 500 Hz. The mid-heavy sound ensures good speech quality, but is not advantageous for videos and music. As usual, this problem can be easily solved by using external speakers, which can either be connected digitally (DisplayPort/HDMI) or, in a conventional way, via analog audio jack. The latter provides a clear and sufficiently loud audio signal through most headphones.

E460, L460, T460, T460p, T460s, and now the X1 Carbon: It appears that Lenovo wants to fill even the tiniest niche with a ThinkPad model. We do not want to judge here whether this is really necessary or reasonable - but help to find the best device for each purpose.

Especially its great mobility is a strong argument for the X1 Carbon.

With an aggressive weight of not even 1.2 kg, you can take the ThinkPad on every business trip and it easily lasts a whole day without power adapter. Despite slim design, the user hardly needs bother about limitations in performance, connectivity, or emissions. On top of that, Lenovo has incorporated a very attractive WQHD panel with great colors and contrasts, which could have, at best, been a bit brighter.

However, there are good reasons to prefer the T460s over the X1 Carbon. In return for its slightly bigger case, you'll get an even crispier keyboard, additional upgrade and connectivity options (native LAN port, SmartCard, SD reader) as well as higher performance reserves thank to an increased TDP. In addition, the price of the T460s is more attractive, yet still very high. All things considered, we would tend to recommend the T series - however, this decision might vary depending on the user.