Portable Mac: Power, Long Battery Life

Tom Thompson

With a 100- or 117-MHz PowerPC 603e at its heart, Apple Computer's latest line of PowerBooks combines RISC-processing power with insanely great battery life. Apple went with the 117-MHz specification for two reasons: 603e yields at 120 MHz were problematic, and Apple doesn't want to repeat the supply shortages that plagued the PowerBook 500 series.

BYTE looked at a preliminary PowerBook 5300c with a 100-MHz 603e and a 10.4-inch active-matrix color LCD screen. The PowerBook 5300c's long battery life is achieved through the power-saving features of the 603e, which saves its internal state while turned off, and the power management software in the Mac OS, which literally switches off the processor between keystrokes. A single lithium-ion battery provides an estimated 3 to 5 hours of battery life.

We used BYTE's Thumper 2 on the PowerBook 5300c and obtained an impressive battery life of nearly 7 hours (see the table). Although Thumper 2 imitates some keyboard activity, the 603e processor switches off between keystrokes, so BYTE's battery-life benchmark number is optimistic. But it does indicate that Apple's 3- to 5-hour estimate for heavy usage appears accurate. Your mileage will vary, depending on your work patterns and the PC Card (formerly PCMCIA) peripherals you use.

Other notable features include a 32-bit I/O bus; a PC Card slot, which holds one Type III or two Type II cards; an infrared communications port; and a storage bay that holds a removable floppy drive or other storage media.

In sum, the PowerBook 5300c racks up Pentium-caliber performance and impressive battery life far beyond what we've seen with 486- or Pentium-equipped notebooks, all in a package weighing in at 6.2 pounds.

Contact: Apple Computer; Cupertino, CA; (800) 776-2 333, (408) 996-1010

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Battery-Life Performance

System                          Hours
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PowerBook 5300c
(100-MHz PowerPC 603e)          6.87

PowerBook 540c
(33-MHz 68LC040,
two Type II NiMH batteries)     6.00

Toshiba 2150CDT
(75-MHz 486DX4)                 5.20

Toshiba T4900 CT
(75-MHz Pentium)                4.25

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PhotoPowerBook 5300c

photo_link (29 Kbytes)

With a 100-MHz processor, 8 MB of RAM (expandable to 64 MB), a 500-MB hard drive, and a 9-1/2-inch dual-scan gray-scale LCD screen, $2200; with a 10.4-inch active-matrix color LCD screen, $3800.