Double Time: New PIII Notebooks Run at 650 or 500 MHz

For months we've been hearing about a technology from Intel called SpeedStep: It's a novel way to conserve notebook processor power. When your notebook is plugged in, the processor runs at its top speed, but when it's running on battery power, it "steps down" to a lower speed. The good news: After some delays, the technology has arrived--and it works. The three Pentium III notebooks we tested ran plenty fast, and battery life on two of the units was outstanding. The surprising news: The notebooks managed almost identical battery life running at either speed, so we see little reason to run them at the slower speed.

Our $4238 Dell Inspiron 7500, $4199 Hewlett-Packard OmniBook 4150, and $4408 IBM ThinkPad 600X test models all came with Windows 98 and 128MB of RAM. (Dell and HP sent shipping units; the IBM unit was a preproduction machine.) If you are in the market for a high-powered bargain, check out sibling 600/500-MHz systems: You won't take much of a performance hit at the lower speeds, and you should save at least $200.

How It Works

Intel's SpeedStep technology, also known by its code name Geyserville, involves three components: the processor, a compliant BIOS that recognizes use of battery or AC power, and a motherboard chip that regulates voltage and speed. By focusing not only on the processor speed but also on the voltage, Intel says, it has reduced power consumption a great deal. And that's true: The new CPUs running at their top speed of 650 MHz consume 14.4 watts of power at 1.6 volts, numbers that plummet to 7.9 watts and 1.35 volts at 500 MHz.

Battery Surprise

But a processor is just one component in a notebook. The screen, for example, gobbles up about 18 percent of the battery power most of the time, Intel estimates. When working at full capacity, the CPU puts a significant drain on the battery, but usually the CPU doesn't work that hard. When you're performing office tasks like word processing or e-mail, notebook power management kicks in, and the CPU runs at only a quarter to a third of its full power, Intel estimates. Under these conditions, even a 40 percent drop in CPU power consumption makes little difference to overall notebook battery life. And that's exactly what our tests show.

The Dell Inspiron 7500, carrying a 12-cell lithium ion battery, won bragging rights as the endurance champ: It lasted a whopping 5 hours, 6 minutes at 500 MHz. When we stepped the Dell up to 650 MHz, battery life still held out for an even 5 hours. HP's OmniBook 4150, with a 9-cell lithium ion battery, lasted 3 hours, 51 minutes at 650 MHz and 3 hours, 48 minutes at 500. The IBM ThinkPad 600X, with a 6-cell lithium ion battery, lasted a less-laudable 2 hours, 40 minutes at 650 MHz and 2 hours, 26 minutes at 500.

Of course, some tasks do push your notebook's CPU harder. If your work involves heavy number crunching or multimedia creation, or if you want to be able to watch DVD movies when you go on cross-country flights, take note. In our informal testing of how well the notebooks ran a DVD movie, we found improved battery life of up to 14 percent when the processor stepped down to 500 MHz. That percentage translates into 21 more minutes of battery life for the Dell unit, for example.

On the speed front, our PIII-650s trounced the previous mobile champs, running approximately 16 percent faster than a PIII-500 notebook on the PC WorldBench 98 test suite. At 650 MHz, the three units finished in a virtual tie: IBM's ThinkPad scored a 269, the HP a 266, and the Dell a 264. At their slower 500-MHz speed settings, the machines turned in scores resembling those of existing PIII-500 notebooks, across a range from 237 for the IBM to 233 for the Dell.

Guts and Bolts

So which of these three notebooks is right for you? A true desktop replacement, the $4238 Dell Inspiron boasts a brilliant 15-inch TFT screen with 1400 by 1050 resolution and a roomy 25GB hard drive. Two media bays accommodate various modules including a combo DVD-ROM/LS-120 disk drive. These modules are not hot-swappable. Unfortunately, this unit weighs 10.5 pounds with the DVD-ROM/floppy disk combo drive and AC adapter. And it's more than 2 inches thick. You'll need a big briefcase when you leave your desk.

The $4199 HP OmniBook 4150 weighs considerably less--only 7.6 pounds with the DVD-ROM drive and AC adapter--but still has robust features for mobile presenters. It includes an 18GB hard disk, a crisp 14.1-inch TFT screen, a touchpad, and a pointing stick. You can hot-swap an array of modules in one media bay.

If you want to shed every quarter-ounce possible and can live with shorter battery life, consider the $4408 IBM ThinkPad 600X, which tips the scales at 7 pounds with its DVD-ROM drive, external floppy drive, and AC adapter. (If you travel without those two drives, you'll save about 1 pound.) Its screen is smaller than the others (13.3 inches), however, and it has a 12GB hard disk. The ThinkPad has one media bay for various modules, but without hot-swap capability.

Do I Hear 750?

Looking ahead, we expect PIII SpeedStep chips to exceed 750 MHz by year's end. Mobile Celeron processors will also get faster, reaching 600 MHz or more--but they won't be getting the SpeedStep technology, according to Intel. AMD plans to release its answer to SpeedStep, code-named Gemini, at midyear in mobile K6-2+ chips starting at about 500 MHz. AMD will also use Gemini technology in mobile Athlon chips, slated to debut later in 2000.

Meanwhile, for thin-and-light notebooks that can't handle the heat requirements of SpeedStep's higher frequency, Intel has recently launched new low-voltage parts--PIII-500 chips running at 1.35 volts, which is the voltage of existing PIII-400 mobile CPUs. And 1.1-volt PIIIs for thin-and-light models will arrive later in the year. Mainstream notebook users, however, can step up to 650 MHz now and enjoy the performance gain.

SUMMARY

Dell Inspiron 7500 $4238 Dell Computer 800/388-8542 www.dell.com

SUMMARY

HP OmniBook 4150 $4199 Hewlett-Packard 800/752-0900 www.hp.com/omnibook

SUMMARY

IBM ThinkPad 600X $4408 IBM 877/426-4727 www.pc.ibm.com