The insatiable demand for storage, reliability and portability is prompting disk drive manufacturers to beef up their portable products, increasing capacity while using faster versions of popular interfaces. A number of leading storage vendors recently boosted capacity and performance for portable drives used in mobile applications and to back up critical files.

Iomega Corp. of San Diego, CA, has unveiled a family that offers a variety of interfaces. The basic model has USB 2.0 compatibility, while other versions add Firewire 400 and Firewire 800 compatibility.

Western Digital Corp. of Lake Forest, CA is focusing on software that automates backup, letting users protect data on demand or automatically. The system's safe shutdown feature ascertains complete backup before the drive is powered down.

Milpitas, CA-based Maxtor Corp. is also focusing on simplicity. Its OneTouch II a redesigned graphical user interface that simplifies setup. The OneTouch II has both USB and Firewire 400 interfaces.

Drives from all three manufacturers now offer storage from 80 up to 250 Gbytes of data, large enough to back up most systems. With larger drives, users can store data for notebooks, desktops and office systems on a single drive. Users can store more than one mirror image of data files, making it possible to recall older software that has since been revised. The drives can also be used to transport many engineering CAD or MP3 files, as well as videos.

The USB 2.0 interface provides a maximum transfer rate of 480 Mbits per second substantially reducing transfer times of USB 1.1 drives. The Firewire versions run at 400 and 800 Mbits/second. Speed of all models is enhanced by a 7,200 rpm platter rotation speed.

Another widely available feature is data security, using passwords to prevent others from accessing data. The drives also claim low noise levels, which is an important factor since the drives are often active whenever the main computer is operating.