Windows ReadyBoost, a performance enhancement feature new with Windows Vista, creates a "cache" of frequently needed data in otherwise unused space on a USB flash drive or flash memory card. This cache remains available even when the computer's random-access memory, or RAM, is fully occupied--speeding up system performance and improving the user experience, especially when multiple or large applications are running.
Windows ReadyBoost works in conjunction with an innovative new memory manager in Windows Vista called Windows SuperFetch. SuperFetch continually analyzes memory usage patterns by looking at multiple factors, such as what applications are running and even the time of day, then accelerates performance by retrieving data it anticipates will be demanded next. This cache of "prefetched" data is typically held in the computer's random-access memory, or RAM, where it can be accessed much faster than from a hard disk.
Windows ReadyBoost taps unused storage space on USB flash drives or flash memory cards to establish a Windows SuperFetch cache. While not as fast as RAM, flash memory can deliver data up to five times faster than a hard disk under certain usages. This makes Windows ReadyBoost particularly suited to improving performance for computers with less than 1GB of RAM.
All versions of Windows Vista come with Windows ReadyBoost enabled by default. When a ReadyBoost-compatible flash drive or memory card is first connected to a computer, Windows Vista displays a window asking users how much of the drive or card's memory should be set aside for Windows ReadyBoost. Whatever space is not designated for Windows ReadyBoost will still be available for storing user data such as digital music, photos and work documents.
All data held in the ReadyBoost cache is encrypted, so there is no security risk if the flash drive or card is lost or stolen. A copy of the cached data is also kept on the computer's hard disk at all times, so no data is lost in the event the flash drive or card is removed.
Flash drives and cards must meet specific technical requirements set by Microsoft to work with Windows ReadyBoost; most existing drives and cards are not ReadyBoost-compatible. To help consumers know what they are buying, SanDisk will add the "Enhanced for Windows ReadyBoost" message to the packaging for its ReadyBoost-compatible flash drives and cards.
The new SanDisk Cruzer Contour, introduced today and due in stores in March, will carry the "Enhanced for Windows ReadyBoost" label. Other SanDisk flash drives with capacities of 1GB or more will also carry the label, starting in mid-February. Select Memory Stick and SecureDigital (SD) cards from SanDisk will carry the label later this year.