One reason for the ThinkPad X31's good performance was that the model we tested had an ATI Radeon Mobility graphics chipset with 16MB of its own memory. By comparison, both the Latitude D400 and the Compaq nc4000 use graphics chipsets that borrow system memory, which can be a drag on performance. The ThinkPad X31's scores varied slightly depending on whether we tested with the default battery or with both the standard battery and the optional extended-life battery, but either way the system was very fast.
Mobile application performance (Longer bars indicate better performance)
The ThinkPad X31 really shined in our battery tests. With its standard 10.8V, 4,400mAh battery, the ThinkPad X31 kept running for more than four and a half hours, easily outlasting both the Dell Latitude D400 (11.1V, 3,900mAh battery) and the HP Compaq nc4000 (10.8V, 3,600mAh battery). In fact, the ThinkPad X31's MobileMark 2002 battery score was a whopping 73 percent better than that of the Compaq nc4000.
And that wasn't the impressive part. When we tested with the extended-life battery, a $190 10.8V 3,600mAh battery that you use in addition to the main battery, the ThinkPad X31 lasted a full eight hours. That's the best score we've ever seen from a mainstream notebook PC, making it money well spent in our book. Among the notebooks we've tested, only the ThinkPad X31 delivers true, all-day computing without ever plugging in.
Battery life (Longer bars indicate better performance)
To measure mobile application performance and battery life, CNET Labs uses BAPCo's MobileMark 2002. MobileMark measures both application performance and battery life concurrently using a number of popular applications (Microsoft Word 2002, Microsoft Excel 2002, Microsoft PowerPoint 2002, Microsoft Outlook 2002, Netscape Communicator 6.0, WinZip Computing WinZip 8.0, McAfee VirusScan 5.13, Adobe Photoshop 6.0.1, and Macromedia Flash 5.0).
Find out more about how we test notebooks.System configurations:
Dell Latitude D400
Windows XP Pro; 1.7GHz Intel Pentium M; 512MB DDR SDRAM 266MHz; Intel 82852/82855 Graphics Controller-0 (up to 64MB shared); IBM Travelstar 40GN 40GB 5,400rpm
HP Compaq nc4000
Windows XP Pro; 1.6GHz Intel Pentium M; 224MB DDR SDRAM 266MHz; ATI Radeon IGP 350M 32MB (shared); Toshiba MK6022GAX 60GB 5,400rpm
IBM ThinkPad X31
Windows XP Home; 1.6GHz Intel Pentium M; 512MB DDR SDRAM 266MHz; ATI Mobility Radeon 16MB; IBM Travelstar 40GN 40GB 5,400rpm
IBM provides a three-year warranty on parts and labor, though the battery is covered for only one year. Onsite service is not included, but you can choose from several extended warranties with onsite or depot repair ranging from two years ($98) to five years ($449). The company covers the shipping costs for warranty repairs. Our only gripe is with IBM's stingy LCD policy: it won't replace an XGA display unless you have a total of nine dead pixels (or eight pixels all stuck in either on or off position).
During the warranty period, you also receive toll-free, 24/7 telephone support. Support calls after that cost $35, but you may never need to pick up the phone. The system help and documentation both on the local disk and on IBM's Web site is comprehensive and well organized, and all of it is easily accessible from the Access IBM button. We especially like that IBM stores a disk image on a separate partition (it uses about 3GB) rather than on a CD, so that you can easily restore the system in an emergency. Alternately, you can use the Rapid Restore utility to back up important applications and data.
To find out more about how this product's warranty really stacks up and what you should look for in terms of service and support, take a look at CNET's hardware warranty explainer.