ARTICLES IN THE BOOK
A GUIDE TO WINDOWS VISTA
This article is from:
All text is available under the terms of the GNU Free Documentation License: http://en.wikipedia.org/wiki/Wikipedia:Text_of_the_GNU_Free_Documentation_License
ReadyBoost is a disk caching technology first included with Microsoft's Windows Vista operating system. It aims to make computers running Windows Vista more responsive by using flash memory on a USB 2.0 drive, SD card, CompactFlash, or other form of flash memory, in order to boost system performance.
ReadyBoost is also used to facilitate ReadyBoot, an updated version of Windows XP's prefetcher which performs analysis of boot-time disk usage patterns and creates a cache which is used in subsequent system boots.
Using ReadyBoost-capable flash memory devices for caching allows Windows Vista to service random disk reads with performance that is typically 80-100 times faster than random reads from traditional hard drives. This caching is applied to all disk content, not just the page file or system DLLs. Flash devices are typically slower than the hard drive for sequential I/O, so to maximize performance, ReadyBoost includes logic to recognize large, sequential read requests and then allows these requests to be serviced by the hard drive.
When a compatible device is plugged in, the Windows AutoPlay dialog offers an additional option to use it to speed up the system; an additional "ReadyBoost" tab is added to the drive's properties dialog where the amount of space to be used can be configured. Up to 4 gigabytes of flash memory can be assigned. ReadyBoost encrypts and compresses all data that is placed on the flash device; Microsoft has stated that a 2:1 compression ratio is typical, so that a 4GB cache could contain upwards of 8GB of data.
According to Jim Allchin, for future releases of Windows, ReadyBoost will be able to use spare RAM on other networked Vista PCs.
For a device to be compatible and useful it must conform to the following requirements: