Intel has turned up the juice on notebook PCs. As expected, the company Tuesday introduced two mobile Pentium III processors, running at 600MHz and 650MHz. Intel also reduced prices on its stable of existing mobile chips. The chips are the first to offer Intel's SpeedStep technology. The design allows notebooks to power down from 600MHz or 650MHz to 500MHz when running on battery power. SpeedStep arose as a response to some of the power-management compromises that notebook PCs present. Intel's research showed that most notebook users spend the majority of their computing time plugged in, so SpeedStep is focused on providing notebooks with maximum performance while plugged in and maximum battery life while not. A new mobile Pentium III notebook will run at 650MHz while running on alternating current. But once the plug is removed a software applet switches the chip automatically to a Battery Optimised Mode, powering it down to 500MHz. The idea behind the technology is to provide the most power while the PC is plugged in but still offer reasonable battery life when it's unplugged. Users, however, can override SpeedStep and run their processors at 600MHz or 650MHz while on battery if they so choose. PC makers take up the cause PC makers responded today with a number of announcements. Notebooks from a number of manufacturers, ranging in price from about $2,500 (£1,550) to more than $4,000, will be available with the new chips almost immediately. Gateway, for example, introduced notebooks at opposite ends of the spectrum. The company's latest Solo 9300 notebook model offers the 600MHz mobile Pentium III and a new 15.7-inch screen for a starting price of $3,499. At the same time, Gateway's newest Solo 2550 offers the 600MHz mobile Pentium III chip and a 13.3-inch display for a starting price of $2,499. Toshiba America Information Systems also announced notebooks, including a Portégé 7200CT with the 600MHz chip and a 13.3-inch screen for $3,699. The company will offer the 600MHz and 650MHz mobile Pentium III chips in its Tecra 8100 series. A model with the 650MHz chip, a 14.1-inch screen, 128MB of RAM and a DVD-ROM drive will ship next month for about $4,199, according to the company. IBM is expected to offer the 600MHz chip in a refresh of its ThinkPad 600 series notebook, coming later in the month, sources said. Dell Computer, Hewlett-Packard and Compaq Computer are also expected to announce notebooks using the new mobile Pentium IIIs. Robert Jecmen, vice president of Intel's architecture business group, touted the new processors, developed over three years, as representing a "generational leap" during the chips' unveiling at a San Francisco news conference. "We've come a long way up to now with evolutionary improvements in the mobile platform, but today I'm really proud to present what I look at as a revolutionary milestone in mobile computing," said Jecmen, who is also general manager of Intel's mobile/handheld products group. "We are not only increasing frequency by a whopping 150MHz, but in addition to that we're introducing a breakthrough capability for the systems to automatically switch between two distinct performance modes," Jecmen said. With the introduction of the new mobile chips, Intel made major price cuts on its existing stable of mobile Pentium IIIs, Pentium IIs and mobile Celeron chips. Mobile Pentium III chips were reduced by up to 54 percent. The largest cut came on the 500MHz mobile Pentium III, which fell 54 percent from $530 to $245. The 450MHz mobile Pentium III chip was reduced by 46 percent to $187. The 400MHz Pentium III was also reduced by 46 percent to $187. Intel's 400MHz mobile Pentium II chip was reduced 45 percent from $358 to $198. Mobile Celeron chips were also reduced in price by up to 54 percent. The largest price cut came on the 466MHz mobile Celeron, which fell 54 percent from $209 to $96. The 433MHz mobile Celeron was reduced by 53 percent to $75, and the 400MHz was cut by 34 percent to $70. Notebook makers are expected to respond with price cuts of their own. Compaq, for example, reduced prices on its Armada notebooks today by up to 20 percent. Prices given are per 1,000 unit quantities. Individual prices vary. PC Week's Anne Knowles contributed to this report. What do you think? Tell the Mailroom. And read what others have said.