When a removable memory device such as a USB flash drive is first inserted into a port, vista checks if it is fast enough to work with the Superfetch mechanism that ReadyBoost uses. If so,we are asked if we want the drive to be used for improving system performance. We can then choose to allocate part of a USB drive's memory to speed up performance and use the remainder to store files.
The performance is drastically improved.In some cases a system whose memory is increased from 512MB to 1 GB through the external plugged device can see the speed improving from 11 sec to 2 sec. The performance is even better in the case of laptop systems as laptops have a relatively low 'rpm's than the desktop systems.It also saves the battery power of the laptops.
