Lenovo ThinkPad X1 Yoga 4th Gen Core i7 Convertible Review: A ThinkPad X1 Carbon in Disguise

Dimensions are nearly 1:1 with the ThinkPad X1 Carbon. However, our ThinkPad X1 Yoga is the heavier model by about 100 g due to the glass touchscreen and metal chassis compared to the carbon fiber makeup of the X1 Carbon. The system is still one of the lighter 14-inch convertibles in the market as the HP EliteBook x360 1040, Asus ZenBook Flip 14, and the Dell Latitude 7400 2-in-1 are all heavier.

A noticeable drawback to the X1 Yoga is its long length due to the thick chin bezel. The smaller Latitude 7400 2-in-1 is easier to carry while offering the same size 14-inch display.

An Intel 9560 comes standard on all SKUs for Wi-Fi 5 or 802.11ac connectivity. There are no Intel AX200/201 options meaning no Wi-Fi 6 connectivity despite the high asking price. We experienced no wireless issues when paired with our Netgear RAX200 router.

The Precision-enabled clickpad (~10 x 5.6 cm) is smaller than the clickpads on both the EliteBook x360 1040 (~11.1 x 6.5 cm) and XPS 13 9300 (11.2 x 6.5 cm) even though the latter is on a 13.3-inch form factor laptop. To make up for this size deficit, the ThinkPad X1 Yoga includes the familiar dedicated mouse keys and TrackPoint that traditional ThinkPad users have grown accustomed to. Common multi-touch inputs like drag and dropping or highlighting text should therefore easier on the X1 Yoga.

Unfortunately on our test unit, the clickpad would frequently pause for a split second and not respond to any movement. This would sometimes occur when clicking on a dedicated mouse key whilst moving the cursor on the clickpad simultaneously. It's an annoying and inconsistent phenomenon that we recommend owners to try for themselves as we cannot confirm if the behavior is intentional or not.

Color space covers approximately 62 percent and 96 percent of AdobeRGB and sRGB, respectively, to be nearly identical to most FHD panels on other flagship Ultrabooks. OLED panels like the one of the 2017 ThinkPad X1 Yoga are able to cover more of AdobeRGB for deeper and more accurate colors than our WQHD IPS panel.

Further measurements with an X-Rite colorimeter reveal a well-calibrated display out of the box with average grayscale and color deltaE values of just 1.7 and 2.07, respectively. Attempting to calibrate the display even further ourselves would result in any major improvements.

Outdoor visibility is poor which is a shame because the convertible form factor will likely encourage owners to work outside of home more frequently. Expect glare and washed out colors on the glossy panel even if working under shade. The wide IPS viewing angles can also only do so much to lessen glare when the backlight is only half as bright as some competitors.

CPU performance is where we expect it to be relative to other laptops equipped with the same Core i7-10510U processor. It's not all that different from the Ryzen 7 3700U or Core i7-1065G7 in this regard. Jumping to the higher-end hexa-core Core i7-10710U SKU will net a 40 percent increase in multi-thread performance assuming that the system won't throttle by too much.

Clock rates will cycle when under prolonged stress much like what we discovered on the recent ThinkPad X1 Carbon equipped with the exact same processor. Our CineBench R15 Multi-Thread loop graph below shows processor performance cycling between 500 points and 660 points whereas the Yoga C940 or HP EliteBook would run slower but more stably. This is explored further in our Stress Test section below.

See our dedicated page on the Core i7-10510U for more technical information and benchmarks.

PCMark results are consistently higher than competitors even though the margins are small. This suggests that performance during real-world workloads can be slightly faster than usual despite the fluctuating clock rates mentioned above. Day-to-day applications benefit the most from short-lived Turbo Boost speeds that the ThinkPad X1 Yoga excels at.

The system exhibits DPC latency issues when opening multiple tabs, playing 4K video, and running Prime95 in sequence. Nonetheless, 4K video will play smoothly with no dropped frames.

The fan will idle when running low loads on the Power Saver or Balanced profile. When on High Performance, the fan kicks into gear at just 29.3 dB(A) against a background of 28.4 dB(A) to be essentially unnoticeable when video streaming or conferencing. In fact, the fan is able to maintain this noise level throughout the entire first benchmark scene of 3DMark 06 for a quiet experience overall not unlike what we found on the ThinkPad X1 Carbon or older ThinkPad X1 Yoga systems.

At worst, we're able to record a fan noise of 38.2 to 39.2 dB(A) when running Prime95. Fan RPM remains constant despite the fact that CPU clock rates will fluctuate when under such conditions.

We can notice no electronic noise or coil whine from our test unit.

Surface temperatures are flat when idling while extreme loads can cause hot spots of 44 C to 50 C. Results are cooler than what we recorded on the Dell Latitude 7400 2-in-1 while being warmer than the HP EliteBook x360 1040 when subjected to similar loads. Perhaps some larger ventilation grilles on the bottom panel could have reduced surface temperatures even further. The convertible never becomes uncomfortably warm to to use since the hot spots are toward the rear of the system and not on the palm rests as shown by the temperature maps below.

We stress the system to identify for any potential throttling or stability issues. When under Prime95 stress, the CPU clock rate cycling behavior mentioned earlier can be observed. Clock rates would boost up to 4.2 GHz for the first few seconds until hitting a core temperature of 97 C. Thereafter, clock rates eventually cycle indefinitely between 2.0 GHz and 3.2 GHz with a cycling core temperature of 69 C to 92 C. This behavior is unlike most other laptops where CPU clock rates and temperatures are fixed when subjected to such extreme loads. The strategy allows Lenovo to squeeze out more performance from the CPU at short bursts albeit at the cost of more unsteady clock rates over time.

Running on battery power will not limit performance. A 3DMark 11 test on batteries returns similar Physics and Graphics scores as the same test on mains.

Idling on desktop demands between 3 W and 7 W compared to 4 W and 14 W on the OLED-equipped 2017 ThinkPad X1 Carbon or 3 W and 13 W on the 4K UHD ThinkPad X1 Carbon. Higher loads like gaming will demand around 43 W to be slightly more than expected for a convertible subnotebook which corroborates with the higher-than-average 3DMark benchmark scores.

The cycling CPU performance has resulted in cycling and unsteady power consumption as shown by our graphs below. When running Prime95, for example, consumption can be as high as 66.5 W or as low as 25 W within a span of just two minutes.

We're able to measure a temporary maximum draw of 66.5 W from the small (~11 x 4.8 x 3 cm) 65 W AC adapter. This AC adapter can be used to charge other USB Type-C devices including laptops and smartphones.