Flash memory stick makers are showing off USB (Universal Serial Bus) drives at Computex that have been certified to work with Windows Vista's ReadyBoot and ReadyBoost functions, which improve boot-up times and the software start-up speeds in PCs.

The certification has been done to ensure users know exactly which flash devices they can use for the function, although it's not necessary. Windows Vista can scan any USB flash device and determine on its own if the device is fast enough and has the correct capacity to work with ReadyBoot and ReadyBoost.

The idea is the same as Intel's Robson technology, except that the flash memory sticks are external devices, while Robson is built inside a laptop PC.

"It's not as fast as Robson," said Dave Lee, product manager for flash memory at Kingston Technology Co. Still, the flash sticks work faster and better than the hard drive for users who don't have Robson in their laptops. Robson is a relatively new technology for laptop PCs, so users with older models can use flash sticks instead. Microsoft is also offering to certify other forms of flash memory, including SD cards and CompactFlash for ReadyBoost and ReadyBoot.

Initially, users need to set up their system to draw on the external flash drive for the speedier boot-up and software launch, said Lee. Flash devices with a Vista-certified logo from Microsoft ensures it works with the OS.

Kingston is showing several devices that have been certified within the past month, as is SanDisk and A-Data Technology Co.