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Lenovo ThinkPad T420 review: Lenovo ThinkPad T420

Lenovo ThinkPad T420

Scott Stein Editor at Large
I started with CNET reviewing laptops in 2009. Now I explore wearable tech, VR/AR, tablets, gaming and future/emerging trends in our changing world. Other obsessions include magic, immersive theater, puzzles, board games, cooking, improv and the New York Jets. My background includes an MFA in theater which I apply to thinking about immersive experiences of the future.
Expertise VR and AR | Gaming | Metaverse technologies | Wearable tech | Tablets Credentials
  • Nearly 20 years writing about tech, and over a decade reviewing wearable tech, VR, and AR products and apps
Scott Stein
8 min read

Compared with laptops seen at CES 2012--ultrabooks and other sleekly designed variations--the ThinkPad T420 is a dinosaur, from the outside, at least. Thick and bulky, with a keyboard studded with enough auxiliary buttons to look like a space shuttle control panel, the T420 is as old-school as a laptop can be. It's also solid as a tank; not a rugged laptop per se, but outfitted with a spill-resistant keyboard and magnesium roll-cage chassis that most laptops don't have. And it's got more ports and features than most laptops, fighting the currently popular minimalist style.


Lenovo ThinkPad T420

The Good

The <b>ThinkPad T420</b> has several things going for it: performance, plenty of ports, excellent battery life, and a very comfortable keyboard.

The Bad

The design of the bulky, business-oriented T420 is positively Stone Age. It's also priced well above similar consumer laptops. No HDMI, no USB 3.0.

The Bottom Line

The Lenovo ThinkPad T420 is as straight-up and unassuming as a business laptop can be on the surface, souped up with faster performance, long battery life, and a flexible selection of ports under the hood.

The ThinkPad T420 is the laptop that escaped from your IT department, and might even be sitting on your desk as we speak. Lovers of older laptop tech won't be disappointed: a rubberized trackpoint sits in the middle of a set of thick, tapered keyboard keys, while large extra trackpoint-controlling buttons sit above the touch pad. You can light your keyboard with a top-mounted LED light next to the Webcam, thank you very much--no backlit keyboard here. Older ports are also here in force: everything from eSATA to ExpressCard, and even FireWire, is included. And, obviously, there's an optical drive (another feature frequently missing from laptops nowadays).

It feels unfair to attack the design of the ThinkPad T420 too much, because it's clearly not meant for the average consumer--this vPro-equipped laptop is all business. However, we can ding the T420 a little on price: our configuration's priced climbed above $1,000, although the ThinkPad T420 starts as low as $749 on Lenovo's Web site for an entry-level version with a Core i3 processor and fewer bells and whistles.

Price as reviewed / Starting price $1,139 / $749
Processor 2.5GHz Intel Core i5-2520M
Memory 4GB, 1,333MHz DDR3
Hard drive 500GB, 5,400rpm
Chipset Intel QM67
Graphics Nvidia NVS 4200M / Intel HD 3000 (Optimus)
Operating system Windows 7 Professional (64-bit)
Dimensions (WD) 13.4x9 inches
Height 1.2 inches
Screen size (diagonal) 14 inches
System weight / Weight with AC adapter 5.2 pounds / 6.1 pounds
Category Midsize

The last time we reviewed a ThinkPad T series was the ThinkPad T410 back in December 2010. In terms of design, nothing's really changed. The ThinkPad T420 is heavy, at 5.2 pounds for a 14-inch laptop, and its body is nearly 1.2-inch thick. Even so, the T420 isn't as hard to heft as you'd expect based on how it looks. What you gain here is durability, port selection, and a surprisingly good mix of speed and battery life. With its slightly faster-than-average Core i5-2520M CPU, the T420 rivaled Core i5 competitors in our benchmark tests, and the included Nvidia graphics are good enough to play a game like Street Fighter IV at medium settings. The battery life topped 7 hours in our CNET tests, besting the Apple MacBook Pro.

As you'd expect, the ThinkPad T420's keyboard is very comfortable: it's the Lincoln Town Car of keyboards, or a comfy orthotic shoe. It may not be sexy, but damned if it isn't a great keyboard for writing. However, the plethora of additional and strangely laid-out function and teleconferencing buttons can overwhelm. The Esc and Delete keys are large, vertical, and elevated above the rest of the keyboard. That's odd, too, but not if you use ThinkPads. Overall, it feels like a command center, and clearly was meant to be thought of as such.

The touch pad isn't very wide for multitouch, but its stippled surface has great traction and sensitivity. Too many buttons above and below the pad may be good for accuracy in tight quarters like on planes, but they cramp the pad's real estate. Multitouch gestures are tough to pull off. Out of curiosity, I gave that red rubber trackpoint another try. I have to admit, there's something to appreciate in the trackpoint's simple efficiency, even its accuracy, but it's not for everyone, and the rubber point can throw off a hunt-and-peck touch-typer such as myself.

Again, this is clearly a laptop made for those who don't want change, who want a laptop that looks the same on the outside as a product from several years ago. If you want change, get a ThinkPad Edge. At least the T420's extra vertical thickness has been well-used to stack ports--a DisplayPort sits above a USB 2.0 port on one side, while USB ports and SD card/ExpressCard slots are stacked on the other.

ThinkPads have always boasted good displays, and the matte-finish 14-inch display on this model was crisp and bright and easy to read. The 1,600x900-pixel resolution is a step up from the standard, offering finer text resolution and more screen real estate, without shrinking icons or menus too much. It also costs $50 as an upgrade over the standard 1,366x768-pixel display. The T420's hinges open the screen up a full 180 degrees from the base for extra flexibility.

The stereo speakers are fine for videoconferencing or office functions, but this isn't a wonderful movie-watching laptop. Streaming Netflix movies looked a little washed-out. Then again, you're not supposed to be using a work laptop like this for movies and games, are you? (In case you're curious, Street Fighter IV did play astonishingly well using the T420's Nvidia Optimus NVS 4200M graphics, running at 39.8 frames per second at native 1,600x900 resolution.)

A high-def 1,280x720 Webcam and included audio optimization settings give the ThinkPad T420 a better-than-average set of teleconferencing tools, although most laptops these days are more than capable of some basic Skype, especially if you wear a headset with a mike. That 720p Webcam, however, is a $30 upgrade that came standard in our configuration.

Lenovo ThinkPad T420 Average for category [midsize]
Video VGA, DisplayPort VGA plus HDMI or DisplayPort
Audio Stereo speakers, headphone/microphone jacks Stereo speakers, headphone/microphone jacks
Data 3 USB 2.0, 1 USB 2.0/eSATA, ExpressCard, mini FireWire, SD card reader 2 USB 2.0, 2 USB 3.0, SD card reader, eSATA
Networking Ethernet, 802.11n Wi-Fi, Bluetooth, optional mobile broadband and WiMax Ethernet, 802.11n Wi-Fi, Bluetooth, optional mobile broadband
Optical drive DVD burner DVD burner


The ThinkPad T420 is flush with ports that would make any owner of older legacy equipment gleam: three USB 2.0 ports (one of them powered), one USB 2.0/eSATA combo, VGA, DisplayPort, mini FireWire, and even an ExpressCard slot. However, it lacks USB 3.0 and HDMI, both of which are more useful in modern work environments.

The ThinkPad T420 offers a number of upgrade options, including some nickel-and-dime upgrades ($20 extra for Bluetooth, $20 for a fingerprint reader, $30 for an HD Webcam, $55 extra for WiMax, $50 for a 1,600x900-pixel display as opposed to 1,366x768 pixels) that can add up quickly. The base T420 comes with a second-gen Intel Core i3 processor, but can be upgraded to our version's Core i5, and even higher to a 2.8GHz Core i7-2640M, which will cost an extra $190 over our midrange model. RAM can be upgraded to 8GB, and you can choose a 500GB hard drive of 5,400rpm or 7,200rpm, or a solid-state drive (SSD) of 128GB for an extra $170, or 160GB for $200.

For the T420, the inside is what counts, and its specs and performance live up to what you'd expect in a mainstream laptop. Its performance closely matched the Dell XPS 14z with a Core i7 CPU, despite our version of the T420 only having a 2.5GHz Core i5-2520M processor. This is a second-generation Sandy Bridge CPU, not one of the upcoming Ivy Bridge processors. It would be more than enough for anyone looking to do some office multitasking.

The included Nvidia Optimus graphics aren't earth-shattering, but provide a nice boost over integrated Intel graphics. They're enough for moderate graphics work and even some gaming.

Multimedia multitasking test (in seconds)
(Shorter bars indicate better performance)

Adobe Photoshop CS3 image-processing test (in seconds)
(Shorter bars indicate better performance)

Apple iTunes encoding test (in seconds)
(Shorter bars indicate better performance)

Video playback battery drain test (in minutes)
(Longer bars indicate better performance)

Juice box
Lenovo ThinkPad T420 Average watts/hour
Off (60%) 0.29
Sleep (10%) 0.68
Idle (25%) 6.81
Load (05%) 44.23
Raw kWh number 36.41
Annual power consumption cost $4.13

Annual power consumption cost

With an attached nine-cell battery (for an extra $50), the Lenovo ThinkPad T420 lasted an impressive 7 hours and 22 minutes in our video playback test. Sure, that's with the extended battery, but it ranks as one of the best battery performances from any recent laptop we've reviewed, beaten only by the HP dv7-6b55dx. It bests the 15-inch Apple MacBook Pro I compared it with, but that laptop has an internal battery with no added cost or bulge.

Lenovo offers a standard one-year warranty on the ThinkPad T420. That can be upgraded in various ways on Lenovo's Web site. For example, add up to four years, along with accidental damage protectionl, for $329. A separate battery warranty extension can also be purchased, up to four years for $139. Lenovo's Web site and customer service offer a solid set of support options, and the included blue ThinkVantage button on the T420 is good for accessing a set of onboard diagnostic tools and support documents.

The Lenovo ThinkPad T420 is exactly what you think it is: a big old-fashioned ThinkPad, but upgraded with current processors and specs. It could do with a partial makeover and more modern ports like HDMI--and it's more expensive overall than we'd prefer for the specs included--but those who crave a new experience in an old comfy pair of enterprise-friendly shoes will get what they paid for.

System configurations

Lenovo ThinkPad T420
Windows 7 Home Premium (64-bit); 2.5GHz Intel Core i5-2520M; 4GB DDR3 SDRAM 1,333MHz; 1GB Nvidia NVS 4200M / 64MB (Dedicated) Intel HD 3000; 500GB Toshiba 7,200rpm

HP Envy 14
Windows 7 Home Premium (64-bit); 2.3GHz Intel Core i5-2410M; 6GB DDR3 SDRAM 1,333MHz; 1GB (Dedicated) Intel HD 3000; 750GB Western Digital 7,200rpm

Dell Inspiron N411z
Windows 7 Home Premium (64-bit) w/ SP1; 2.3GHz Intel Core i5-2410M; 8GB DDR3 SDRAM 1,333MHz; 64MB (Dedicated) Intel HD 3000; 750GB Western Digital 7,200rpm

Toshiba Satellite E305-S1990X
Windows 7 Home Premium (64-bit); 2.3GHz Intel Core i5-2410M; 4GB DDR3 SDRAM 1,333MHz; 64MB (Dedicated) Intel GMA HD; 500GB Seagate 7,200rpm

Gateway ID47H02u
Windows 7 Home Premium (64-bit); 2.3GHz Intel Core i5-2410M; 4GB DDR3 SDRAM 1,333MHz; 64MB (Dedicated) Intel GMA HD; 500GB Western Digital 5,400rpm

Find out more about how we test laptops.