Readyboost is a technology in Windows that was introduced in Windows Vista and improved for Windows 7 by Microsoft. The technology basically allows the computer user to select a flash drive for memory caching. The effect is noticeable on computer systems with 1 Gigabytes or less of computer memory installed. The thinking behind this is that flash memory offers in general a better performance than platter based hard drives.
The improved Readyboost technology in Windows 7 now supports a maximum cache size of 32 Gigabytes opposed to the 4 Gigabyte limit in Windows Vista. Windows 7 also supports up to eight Readyboost devices compared to one in Vista and can improve the startup performance as it can be used during startup as well.

