Lenovo ThinkPad X31 2672

How long will it be until the electronics industry makes major breakthroughs in battery power? While we wait, power-conserving computer chips can do more with less--at least if Intel's new Pentium M is any indication. The low-power processor shows up in IBM's ThinkPad X31 and delivers impressive working time in an ultralight system. You can configure the X31 as a true-blue Centrino, though the model we tested uses IBM's 802.11a/b Wi-Fi and built-in Bluetooth. Beyond its 4.5-hour battery charge, the X31 offers flawless design and flexible configurations. The ThinkPad X31 makes a desirable package for someone who travels a lot and relies on long-running batteries.

IBM's painstaking industrial design makes the ThinkPad X31 a pleasure to use. Its case is made of a sober-looking, matte-black plastic, with the company's signature lip extending from the closed lid's edges to seal around the base. For a notebook with no floppy or optical drive, the X31 is on the big side, at 10.75 inches wide, 8.75 inches deep, and 1.25 inches thick. Despite these dimensions, though, it weighs just 3.6 pounds (4.3 with the power cord and the AC adapter). That's comparable to other ultralight weights, despite the X31's large proportions.

For $199, you can attach a snap-on dock called the UltraBase, which adds stereo speakers, a battery charger on the bottom, and a swappable bay; a combo DVD/CD-RW drive for that bay costs $299. With the dock, the X31 can actually have three batteries installed at the same time: the notebook's main battery, another main battery in the dock, and a battery in the dock's drive bay. The UltraBase adds an inch to the X31's thickness and 1.9 pounds to its heft, so if you're traveling, just toss the dock in your suitcase and plug in an external battery to the dock connector, and you'll still have a spare.

The dock and the notebook cooperate well. To separate them while the system is running, push the blue button on the dock's front edge and wait for an onscreen message, then pull the lever on the left side, and the notebook pops up. To reconnect them, just slide the notebook toward yourself along the face of the dock, and it flops into place. The dock can come in handy for charging the notebook's main battery when you leave it in your hotel room. Unfortunately, only the notebook itself can charge the external battery.

Two catches hold the X31's lid snugly closed. And when you open the lid, thick steel hinges keep it right where you position it. The lid folds all the way back, so you can stand up at a desk or a podium and look straight down onto the 12.1-inch (diagonal) screen. The keyboard clatters too much when you type, but it feels extremely tight and responsive. The keys are surprisingly big, with no wiggle whatsoever, and the keyboard doesn't sag a bit. Instead of a touchpad, the X31 has a pointing stick embedded between the G, H, and B keys. Pointing sticks can be irritating because they're hard to steer without typing in a random G or H, but this one comes with a mushroom-shaped tip to prevent that. IBM packs the X31 with the original eraserhead tip and a new shape as well, but we think that the mushroom tip will be a big success.

We're not joking when we say that the ThinkPad X31 is packed with features. The left edge sports a USB 2.0 port, a combination CompactFlash/Microdrive memory slot, a Type II PC Card slot, a rare FireWire port, and an infrared port. The back edge offers parallel and monitor ports, another USB 2.0 port, and a gigabit Ethernet and a modem port. The dock adds a PS/2 port for an external mouse and a serial port for syncing your PalmPilot. The notebook lid conceals wireless network antennae for Bluetooth and Wi-Fi, and inside the notebook are IBM transceivers for both network schemes; you can easily turn these on and off using the F5 key. IBM also builds in its Embedded Security Subsytem 2.0--a processor that authenticates notebook users and encrypts wireless and wired communication--as standard equipment.

Under the hood, the X31 features a comfortably large 40GB hard drive but only 256MB of PC2100 DDR memory, though you can bump up the memory to 512MB. The X31 takes either a 1.3GHz or a 1.4GHz Pentium M, making it fast enough for basic productivity tasks, though not as speedy as competing PM systems that feature 1.5GHz or even 1.6GHz processors. Our performance tests bear out that performance hit. The X31's standalone ATI Mobility Radeon graphics controller, with just 16MB of its own memory, produced bright, saturated colors and good focus on a 1,024x768 screen but, sadly, came in dead last in our 3D performance tests.

Mobile application performance
The IBM ThinkPad X31 is the first Pentium M-based ultraportable CNET has tested (the previous systems were thin-and-lights). At 1.4GHz, its processor is also the slowest Pentium M we've seen. Only its 5,400rpm hard drive kept it in range of the competition--just four points behind the Gateway 450, with its 4,200rpm hard drive. All in all, though, the X31 is fast enough to compete with Pentium 4-M systems with greater gigahertz.

SysMark2002 performance
The IBM ThinkPad's maximum-performance scores followed its processor speed. As the slowest of the Pentium M notebooks that we've tested, predictably, the X31 came in third in office productivity and Internet content creation. The system's fast hard drive did, however, keep it within one point of the Gateway 450. Compared to its Pentium M brethren, the IBM ThinkPad X31 came in last in maximum performance, but the system is still fast enough to compete with Pentium 4-M systems of faster speeds.

3D graphics performance
The 3D score nearly always comes down to the quality of the graphics adapter and the speed of the CPU. In this case, the IBM ThinkPad X31's ATI Mobility M7, with just 16MB of video RAM, doesn't do it any favors. This system simply was not made with gaming in mind; it came in dead last in our 3D performance test. If you're looking for a gaming machine, keep looking.

System configurations:

Dell Inspiron 600M
Windows XP Professional; 1.6GHz Intel Pentium M; 512MB DDR SDRAM 266MHz; ATI Mobility Radeon 9000 64MB; IBM Travelstar 40GN 40GB 5,400rpm

Gateway 450
Windows XP Professional; 1.6GHz Intel Pentium M; 256MB DDR SDRAM 266MHz; ATI Mobility M7 32MB; Toshiba MK6021GAS 60GB 4,200rpm

IBM ThinkPad X31
Windows XP Professional; 1.4GHz Intel Pentium M; 256MB DDR SDRAM 266MHz; ATI Mobility Radeon 16MB; Hitachi DK23EB-40 40GB 5,400rpm

The IBM ThinkPad X31 continues the Pentium M tradition of great battery life. The system lasted four and a half hours in our battery-life test, coming in second place behind the Gateway 450 in our comparison. The IBM ThinkPad X31 tested with a 10.8V, 4,400mAh battery, which, specificationwise, is not the most impressive battery. The Dell Inspiron 600M, which has a similar, 11.1V, 4,320mAh battery, was unable to even come near the IBM ThinkPad X31's battery life, largely because the IBM ThinkPad X31's slower processor draws less power from the battery, allowing it to last longer. The Gateway 450, which lasted 41 minutes longer than the IBM ThinkPad X31, compensates for its high processor speed with a powerful 14.8V, 4,200mAh battery.