Before you start
Objectives: Learn what is ReadyBoost, why is it used, and what are its requirements.
Prerequisites: you should know what is virtual memory.
Key terms: ReadyBoost, flash, USB, drive, memory, GB, access, RAM, Windows, disk, fast, cache
What is ReadyBoost
USB flash drives are often used for file storage but since Windows Vista, we can also use a USB flash drive to speed up our system. This is done by using USB ReadyBoost feature. USB ReadyBoost allows us to use our flash drive as additional RAM (for memory cache to be exact). In contrast to pagefile access from the hard disk, USB access is much faster (but still much slower than RAM access). Of course, pagefile and ReadyBoost can be combined. You can think of ReadyBoost as a faster alternative to hard disk access (pagefile access). In fact, ReadyBoost puts memory pages on both the USB flash drive and in the pagefile on the disk. That way Windows will still be able to access memory cache if the USB flash drive becomes inaccessible. Data on the flash drive is compressed and encrypted using 128 bit AES.
USB Requirements
When we insert a USB flash drive, Windows will check if it is fast enough for ReadyBoost. USB flash drive must use FAST flash memory in order to be used for ReadyBoost. When buying flash drive, we should check its specification to ensure that it uses FAST flash memory (at least 2.5 MB/s for random 4K reads). The size of the free space on the flash drive which will be used for ReadyBoost can range from 256 MB up to 4 GB. It is recommended to use a USB drive with the same capacity as our total physical RAM, or a higher ratio (2:1 or 3:1). For example, if we have 4 GB of RAM we should use a 4 GB flash drive for ReadyBoost, if we have 2 GB of RAM we should use a 2 GB or 4 GB flash drive, etc. ReadyBoost will not work with USB 1.0 or 1.1 devices. ReadyBoost can only be enabled on one device. ReadyBoost can also be utilized with CompactFlash (CF) or Secure Digital (SD) memory cards. ReadyBoost can only use free space on the flash device. Flash memory reserved by ReadyBoost cannot be used for data storage.
If Windows can use the device, Auto Play will give us the ‘Speed up my system using Windows ReadyBoost’ option. We can also configure ReadyBoost at any other time by using the settings on the ReadyBoost tab of the device properties.
Don’t confuse ReadyBoost for ReadyDrive. ReadyDrive is used with hybrid drives (they include flash memory), and it is not related to ReadyBoost. ReadyBoost is also supported on Windows 7 and Windows 8.