You might have noticed the Intel Centrino advertisements that are suddenly appearing everywhere, including on buses, buildings, signposts, newspapers, magazines, and Web pages. The Centrino is Intel's first-ever, designed-from-scratch, mobile-oriented notebook computer chipset, and after working with a few different Centrino-based machines during the past few months, I'm becoming a convert. Like many of you, I spend much of my time on the move, be it locally around my home office, in town for meetings, or across the country. For this reason, I've been investigating various mobile-computing solutions to find the perfect balance between portability and performance, which is how the idea for Laptop of the Month began. And the Centrino notebooks I've examined so far are pretty close to perfect.

Historically, notebook computers have been a compromise. I can get ultramobile notebook computers, but they pack performance-challenged Pentium III Processor - M or Transmeta's Crusoe chips into a tiny package that typically lacks an integrated optical drive, large hard disk, or a keyboard large enough for my enormous hands. Furthermore, many of the tiny screens on these devices are difficult to read and feature less-than-optimal resolutions. On the other end of the spectrum are the desktop-replacement notebooks, typically behemoths that can carve a notch into your shoulder before you even get on the plane. These 8- to 12-pound devices typically feature massive screens, multiple optical drives, more ports than my desktop computer, and even desktop-style CPUs. But desktop replacements are tough on battery life and weigh a ton, which makes them hardly portable. Good luck opening a desktop replacement on a plane when the person in front of you decides to recline his or her seat.

In the middle of these two notebook groups are the midlevel notebooks. These devices are the true compromise machines and the ones I've typically favored. Midlevel notebooks feature Pentium 4 Processor - M processors, 14" screens, an integrated optical drive, good expandability, and decent battery life. They fall--by feature set, size, and weight--right in the middle of ultramobile and desktop-replacement notebooks. Midlevel devices offer decent performance and battery life, they're not too heavy or too small, but they're not perfect. Any device that's, by design, a compromise across the board, is never going to perfectly suit any particular task.

Then along comes the Centrino. A few years ago, Intel decided to change course and develop a new mobile chipset from scratch, rather than retrofit its desktop chips for the notebook market, as it has done in the past. Part of the reason for this sea change, frankly, was competition from Transmeta, which had always designed its chips with mobility as the first goal. But Intel's design, coming as it does from the world's largest microprocessor vendor, is more interesting than the Crusoe, which offers decent battery life but miserable performance. Centrino provides both better performance and battery life than the competition.

A Centrino-based notebook has three main components. The first component is the CPU, which is confusingly dubbed the Pentium M processor. Intel Pentium M processors typically run at 1.3GHz, 1.5GHz, or 1.6GHz but offer overall performance that rivals a 2.0GHz Pentium 4 Processor - M processor. The Pentium M is more power-management savvy than the Pentium 4 Processor - M or Pentium III Processor - M processors and automatically switches its clock frequency to meet your needs, increasing battery life in ways that are impossible with other chips. I've noticed Pentium M processors operating at anywhere from 200MHz to 1.6GHz on battery power (they remain at their top-rated speed while plugged in, of course). The second Centrino component is the supporting chipset, which Intel designed with power management in mind and features integrated USB 2.0 support. The third component is 802.11b (and, in the near future, 802.11a) support, also integrated directly into the supporting chipset. This design means that Centrino's wireless support is more battery-friendly than the mini-PCI or PC Card solutions that other notebooks use. What all this adds up to is a chipset that hardware makers can use to make small, light machines that are surprisingly powerful. An end to the notebook compromise? This could be it.

Laptop of the Month: IBM ThinkPad T40 And that brings us to this month's Laptop of the Month, the IBM ThinkPad T40, one of the first Centrino-based notebooks. IBM's ThinkPad T series is like a luxury car among more pedestrian notebooks, and the line has always featured surprisingly slim designs, beautiful screens, and IBM's best-of-breed keyboard. The T40 is no exception, and with this device IBM has pulled out all the stops. The T40 that I reviewed features a 1.6GHz Pentium M processor, a gorgeous 14" Thin Film Transistor (TFT) screen running at 1400 x 1050 resolution, a 40GB hard disk (up to 80GB drives are available), 512MB of RAM, integrated 802.11b and Bluetooth wireless technology, two USB 2.0 ports, an IBM ThinkPad UltraNav pointing system with both TrackPoint and thumbpad devices, and an ultraslim DVD/CD-RW combination drive. IBM included the ultraslim drive because the T40 is extremely thin--just 1"; the laptop also weighs just 4.5 pounds.

Despite its slight weight, the T40 outperformed every notebook I've ever tested, including a few 2GHz Pentium 4 Processor - M machines, and my desktop PCs. It can handle massive multimedia tasks, including processor-dependent video encoding, faster than my two 1.8GHz desktop machines, which astonished me. I also threw a few high-end games at the system, including the graphics-card-busting Unreal II, and the T40 handled them without hiccupping. Needless to say, Microsoft Office applications, Adobe Photoshop, and other mainstream Windows applications performed well also.

The T40's battery life is also amazing, especially considering the so-so results I've seen with most Tablet PCs lately. Using IBM's extended battery, which hangs extends about 1" off the back of the machine and adds about a half pound to its weight, I was able to get 4 to 5 hours of battery life during a recent business trip to San Francisco. If I'd been a bit thriftier with the screen backlight, I probably could have picked up even more time, and IBM says the machine can get up to 7 hours on one battery. I wonder if we've reached the point at which the two main problems with notebook computers--performance and battery life--have simply vanished.

I'd like to see IBM cut the width of this machine a bit--it has an additional .5" on each side of the keyboard, for example--and my eyes are a bit old for the high-resolution screen, although less strain-inducing resolutions are available. But other than these few nits, and an occasional graphics display glitch when coming out of Hibernation mode, the T40 has wholeheartedly changed my outlook about what a notebook computer can be. Although I understand that markets for ultramobile and desktop replacement machines will always exist, I'll have difficulty accepting the compromises of each when I know the perfect solution is sitting right in the middle. If you're in the market for a notebook computer, you need to consider Centrino-based devices first. And if you're looking for a top-of-the-line, no-compromises notebook, the T40 has no peer. (The T40 line starts at about $1700; however, the high-end model I tested lists at $3350.) I highly recommend this notebook.