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The ThinkPad X12 Detachable Gen 1 is is Lenovo’s answer to the very good Microsoft Surface Pro 7+. Both are tablets with detachable keyboards and a business bent. While the Surface Pro 7+ has high-end cachet, however, the ThinkPad X12 is more about value.
This review is part of our ongoing roundup of the best laptops. Go there for information on competing products and how we tested them.
Lenovo ThinkPad X12 Detachable Gen 1 (20UW0012US) basic features
Of the seven different configuration options of the ThinkPad X12 Detachable Gen 1 on Lenovo’s website, our review unit (the 20UW0012US, $2,229 on Lenovo.com) seems to be popular, going in and out of stock as we wrote this review. The tablet sold out on Amazon, as well. (When it’s in stock, however, Lenovo priced the tablet quite affordably: $1,331.40 at press time after extensive discounts, the cheapest of the tablets we’ve reviewed.) The Lenovo offers other basic configurations of the X12 Detachable that start with 8GB of RAM, which we’d consider a bit skimpy if other options are available.
Here are the rest of the main specifications. Where there are many options (such as with CPU, RAM, etc.), the features on our specific model are indicated by the words “as tested” in parentheses after the item.
Memory: 8GB-16GB LPDDR4x 4267MHz (soldered) (16GB as tested)
Storage: 256GB/512GB/1TB PCIe SSD
Graphics: Intel UHD (Core i3), Iris Xe
Ports: USB-C (Thunderbolt 4/USB4, DisplayPort, Power Delivery, Data Transfer, 40 Gbps), USB 3.2 Gen 2 (10Gbps), 3.5mm jack, optional nanoSIM
Security: Windows Hello depth camera / fingerprint reader
Camera: 5MP (user-facing) / 8MP (rear facing)
Battery: 42.2Wh (design), 41.9Wh (full)
Wireless: Wi-Fi 6 (802.11ax 2×2), Bluetooth 5.1
Operating system: Windows 10 Pro
Dimensions: 11.15 x 8.01 x 0.34 inches
Weight: 1.67 pounds, 2.4 pounds with keyboard (measured)
Prices: Starting at $1,829 (less with discounts, if active) at Lenovo and Amazon ($2,229 as tested)
While Microsoft’s Surface tablets have always been aimed at a broad market of creators, consumers, and professionals, Lenovo has aimed its ThinkPad purely at professionals—and it shows in the design.
The ThinkPad X12 Detachable Gen 1 maintains the boxy, black ThinkPad aesthetic, using a magnesium alloy for the chassis material. Though just a smidgen thicker than the Surface Pro 7+, the squared lines really contribute to the idea that this is indeed a “detachable,” which favors keyboard use, rather than a traditional tablet that could take it or leave it.
A wedge kickstand reclines almost flat, to about 10 degrees off the horizontal. You’ll have to do some fumbling about to find the small tab that folds it out, though. The kickstand supports the ThinkPad X12 Detachable firmly until its point of greatest recline, where it becomes somewhat springy.
If there’s anything I truly hate about the ThinkPad X12 Detachable, though, it’s the anemic grip that the keyboard has on the tablet itself. With the keyboard unfolded, moving the Detachable around the house usually means grabbing the tablet itself…and off pops the keyboard, time and again. Even worse, the tablet doesn’t always electrically reconnect to the keyboard when reattached, meaning that I had to fiddle with it—disconnect, reconnect—until it finally worked. It’s not a great look when you have to pop the keyboard on and off to allow a product like the ThinkPad X12 Detachable Gen 1 to work out of the box.
That’s before the ThinkPad X12 Detachable went overboard. As I was finishing the review, I put the attached tablet and keyboard on my lap. The keyboard released its grip, and the tablet tumbled backward, landing on my toe. The display bowed out from the frame. I was able to snap it back in with no apparent loss of performance, but still—Lenovo needs to fix this. The combination of the weak magnetic grip and the thin, narrow edge of the kickstand means that the ThinkPad X12 Detachable should be left on a desk, not your lap. We informed Lenovo of our experiences, and the company did not comment.
The ThinkPad X12 Detachable includes venting in the side and top of the tablet, and it emits an occasional faint hiss while under normal use. It’s generally almost quiet during normal use. However, the tablet seemed particularly sensitive to the ambient temperature of the room. We’ll explore this further later on in the review.
For connectivity Lenovo has gone wholly USB-C, with a pair of ports on the left-hand side. Look closely: A faint glyph next to the upper port indicates the presence of Thunderbolt 4/USB 4. You could also use a USB-C dock with the lower port. Though the tiny 65W USB-C power brick could be used in either port, the small plug symbol tells you it should be used on the plain USB-C one. I was worried that the Thunderbolt cables that come with some portable Thunderbolt docks like our Editor’s Choice-winning pick, the IOgear Thunderbolt 3 Travel Dock, might be too short to connect to the tablet without dangling the dock in the air. After trying a few, though, that doesn’t seem to be the case.
The optional SIM slot on the side of the tablet pops out with a standard SIM tool. Lenovo also splurged for a backplate for the SIM caddy, lessening the chance that your SIM card will slip through and onto the ground.
Lenovo’s display isn’t anything to write home about, but the matte screen puts out a comfortable 398 nits max, enough for a well-lit room. According to our colorimeter tests, the display covers 98 percent of the sRGB color gamut, but just 73 percent of AdobeRGB and 74 percent of the P3 gamut. That might not be color-accurate enough for content creation, but fine for everything else.
Keyboard, audio and webcam
Lenovo has always had an elite reputation for its keyboards, and the ThinkPad X12 Detachable’s is pretty good. Naturally, the key travel (1.3mm, according to a Lenovo representative) isn’t quite as deep as a traditional notebook would allow, but there’s smooth, consistently firm resistance, and the keys are large enough (about 1.5mm square) to be comfortable. My fingers initially felt cramped, but my typing improved over time. The two levels of keyboard backlighting can be controlled via the keyboard itself (Fn + Space), and also via an excellent commercial version of the Vantage system utility.
The iconic red TrackPoint remains in the center, with a touchpad below. The ThinkPad X12 Detachable’s touchpad is small, and constrained somewhat by the discrete buttons at the top—a legacy feature from earlier ThinkPads. They’re dependable, though. Lenovo’s touchpad is otherwise smooth and clickable most of the way up and down its length. Gestures worked as expected.
The Lenovo ThinkPad X12 Detachable Gen 1’s audio is subpar. Lenovo includes Dolby Audio Premium enhancement. When the Dolby feature is disabled, music sounded vaguely underwater, jumbled together unpleasantly. Enabling Dolby’s technology couldn’t entirely save it. While the volume is sufficient, make sure to pack headphones or earbuds for a decent aural experience.
The tablet’s user-facing webcam offers 1080p resolution, rather than the more typical 720p cameras that accompany most laptops and tablets. This makes for a sharper image. On the other hand, I was disappointed by the washed-out color and lighting, which feels like it falls short of what we should expect in 2021, post-pandemic. A second, front-facing 8MP camera can be used to take photos or videos of things taking place in front of you.
Lenovo also includes a tiny, manual lens shutter for the webcam. Once closed, a small red dot covers the camera lens. The camera lens is completely blocked, and apps that use it (such as the Windows Camera app) will simply report that no camera is present. My only criticism is that you may need a spare fingernail, nail file, car key or something to catch the tiny slide and slide it over; a fingertip doesn’t always work.
The webcam works in conjunction with the in-keyboard fingerprint reader to provide one of the most convenient biometric experiences in computing today. (Both are Windows Hello-certified, and both ship standard with the tablet.) In fact, I had to do a lot of ducking just to allow my finger time to be read before the wide-angle depth camera picked up my face.
Apps: Glance is a cool privacy utility
Lenovo kept the ThinkPad X12 Detachable Gen 1 relatively bloatware-free, but there are two apps that stand out. First, there’s a commercial version of the Lenovo Vantage app, Lenovo’s superior system utility which can be used to control a number of aspects of your PC. It’s well-organized and powerful.
Glance by Mirametrix is also intriguing. It’s a bit like the Tobii eye-tracking technology that we first wrote about several years ago, but with a privacy bent. The app offers several components, many predicated upon what the depth camera can see of your face. If enabled, presence detection looks to see if you’re at the helm. Look away for too long, and the app blurs your display for privacy’s sake. If it can “see” another person behind you, it will do the same. Leaning too close? A warning will pop up for you to adjust your posture. The app will even smartly remind you to look away from the screen every twenty minutes or so to relieve your eyesight.
Glance struggles with external displays, though. The “smart pointer” component also supposedly teleports your mouse cursor to an external display, but it never worked. The app required a bit of fiddling to blur my external monitor, too.
Lenovo’s ThinkPad X12 Detachable Gen 1’s sober black design communicates that it’s designed for productivity first and foremost. Our real-world tests showed that it handles the demands of the work-from-home office fairly well, although I had to train myself to move the X12 Detachable with one hand on the keyboard and the other on the tablet…or simply fold it up.
Real-world performance tests were satisfactory. The tablet’s 16GB of memory is more than enough for web browsing and Microsoft 365 office apps, and the tablet dropped only 8 frames out of 10,000 when tested against a 4K/60Hz YouTube video. I actually noticed the YouTube skip a time or two, but it happened so infrequently that it never became irritating in the slightest.
While we eventually expect a competing tablet from Dell’s Latitude line, it’s currently a two-horse race between it and the Microsoft Surface Pro 7+. (In the graphs following, the Surface Pro 7+ is highlighted in yellow.) The race is close, though the differences aren’t profound. We’ve also included the older Surface Pro 7.
Remember that Microsoft dials down the Windows power/performance slider to minimal levels, while Lenovo maxes it out. We show the Surface Pro 7+ results at both that default, and dialed up to prioritize performance, to compare with the Lenovo. The yellow bar surrounded by black is what we recorded with the power/performance slider dialed up to “Best performance.”
Our performance evaluations begin with UL’s PCMark 10 suite, which has replaced the older PCMark 8 suite in our testing. PCMark 10 measures everything from videoconferencing apps to web browsing to office apps to CAD renders, using real-world apps when it can. Here, the ThinkPad X12 does better than the Surface Pro 7+ in either performance mode.
We’ve also compared the tablet using the older PCMark 8 suite for backward compatibility. Both are still relevant, though PCMark 10’s tests are more taxing. The Lenovo ThinkPad X12 Detachable again comes out a little ahead of the Surface Pro 7+.
Our Cinebench CPU test uses Maxon’s rendering tool to stress-test the CPU in short bursts, as most tasks do. We use the older R15 test for compatibility’s sake. Cinebench measures how powerfully the ThinkPad X12 will run under most loads, not really factoring cooling into the equation. Here, the Surface Pro 7+ in performance mode takes the lead.
We run a similar test using the R23 version of the benchmark, however, which adds a “thermal throttling” element. In that test (not shown in a chart), the ThinkPad X12 Detachable Gen 1 performance dropped by about 15 percent.
We normally test thermal stress by running HandBrake, another real-world tool that transcodes movies into a format a tablet can use, taxing the CPU for longer than Cinebench does. Here, where shorter bars are better, the ThinkPad X12 drops further back in the pack.
Finally, we look at UL’s 3DMark benchmark to evaluate 3D performance. We normally would use the more advanced “Time Spy” benchmark here, but we first used the older ‘Sky Diver” benchmark instead for compatibility with older tablets. The Iris Xe GPU inside Lenovo’s tablet holds up respectably here, fourth out of five leading results.
As noted above, performance does seem to depend upon the ambient temperature. In a climate-controlled office, we’d expect GPU performance to be consistently stable. But even in an air-conditioned home, the tablet seemed to be sensitive to slight changes in temperature. The tablet passed one 3DMark thermal stability test and failed another.
We also added the more modern Time Spy test, though with a comparison against different, more modern laptops.
How well will a thin, light tablet last against the demands of all-day computing? Battery life is our last test, where we set the screen to a fixed brightness level and then loop a movie over and over until it expires. The Lenovo’s ThinkPad X12 performed about as well as we’d expect, at about 9 hours and 20 minutes of battery life. Unlike some of its competition, however, there’s no quick-charging option, and the tablet required over two hours to charge fully.
Conclusion: A value buy
Lenovo has a respected history in the tablet market. I fondly recall the Lenovo ThinkPad X1 tablet, especially the smart kickstand design that the company, sadly, later abandoned.
I’m left thinking that Lenovo’s return to the tablet market after a year or two off feels a little lacking. Of the two Tiger Lake tablets I’ve tried, Microsoft’s Surface Pro 7+ feels like the superior offering, both in physical design as well as in several of our benchmarks.
That said, the ThinkPad X12 Detachable Gen 1 would suffice for day-to-day office use, and it’s much more affordable than the Surface Pro 7+. From a value perspective, the Lenovo ThinkPad X12 Detachable Gen 1 is clearly the superior tablet.
This review was updated on August 10 to add the Time Spy benchmark results and then on August 16 to update pricing. Our conclusion remains unchanged.