ReadyBoost is a disk cache component of Microsoft Windows, first introduced with Microsoft'sWindows Vista in 2006 and bundled with Windows 7 in 2009. It works by using flash memory, a USB flash drive,SD card, CompactFlash, external hard drive or any kind of portable flash mass storage system as a cache. ReadyBoost is also used to facilitate SuperFetch, which allows it to perform analysis of boot-time disk usage patterns and creates a cache which is used in subsequent system boots."
If you are using a high configuration PC, It doesn't show any effect on speed because if you are a normal user I think only a few times you use your full ram memory but if you are using an old pc with low ram memory(Like 512 MB or IGB) and harddisk & using vista or 7. It speed up your PC and you will see the result, reduced application data loading time, reduced shutdown and restart time and many more you can't imagine without High ram memory. How to use this feature
Step 1: Insert your USB Pen Drive . Go To " My Computer". Format it with FAT32 or NTFS.
How To Format A Pen Drive?
Step 2: After formatting, Right Click on your External Device Volume, and Click on Properties.
Then click on Ready Boost tab.
Step 3: On clicking Ready Boost tab, you will find three radio buttons.
1. Do Not use this Device
This is default. This implies that you do not want this external device to be used by Ready Boost application.
2. Dedicate this device to Ready Boost
If you select this option, your external device (Pen Drive) will be used by Ready Boost completely.
3. Use this device
If you select this option, you can allocate particular space to be used by Ready Boost.
Step 4: After Step 3, you will find this :
After completing all the steps above, you will find that computer has started to function more faster than before .