ReadyBoost is a feature available in Windows Vista, Windows 7 and Windows 8 that provides improved performance to any computer by simply adding a USB flash drive.
USB flash drives of any size can be used with ReadyBoost, so even a small 512mb or 1gb flash drive is suitable. ReadyBoost works by saving the most recently used files inside a file named ReadyBoost on the flash drive. Since USB flash drives can read files faster than a hard drive, Windows Vista/7/8 will rely on the USB flash drive to read files it uses frequently.
For even greater performance, Windows 7 and Windows 8 support more than one USB flash drive and will operate multiple flash drives as a RAID 0 striped array. Using two or more USB flash drives with ReadyBoost will provide great gains in performance. Windows Vista is limited to a single USB flash drive with a maximum of 4gb, while Windows 7 and Windows 8 support ReadyBoost cache files up to 32gb on either a single flash drive or spread across up to 7 flash drives.
We recommend adding a USB flash drive to any computer using Windows Vista/7/8 and enabling ReadyBoost. In addition to USB flash drives, other types of flash memory are supported. For example, many laptops have an internal empty PCIe slot that can be used for a flash drive, or a Secure Digital (SD-card) slot. Using a PCIe or SD card allow the flash memory module to stay inside the computer instead of sticking out like a USB flash drive.
Simply insert an unused and empty flash drive in the computer and it will prompt to enable ReadyBoost.