Windows ReadyBoost

Windows ReadyBoost

Applicable for Windows Vista and Windows 7.

Also applicable for Windows XP through 3rd party softwares main link

With Windows ReadyBoost, you can use (USB) flash drive, memory card, external hard drive to improve performance of your PC without having to buy RAM. USB cost cheaper and at the same time it can be used as a storage device.

Windows ReadyBoost relies on the intelligent memory management of Windows SuperFetch and can significantly improve system responsiveness. [source]

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.

SuperFetch is a technology that pre-loads commonly used applications into memory to reduce their load times, in a similar fashion to the preload in Linux. [source]


What many people failed to realized is that newer PCs, with quick hard drives like the Western Digital Raptor (for example) don't necessarily see the same impact from ReadyBoost as first thought. It's really only older computers, which have been upgraded to Microsoft Windows Vista but barely meet the minimum operating system requirements, that potentially benefit from ReadyBoost. [source] But you could still try if ReadyBoost will benefit your PC.

But accordign to some test the advantage can only be experience when your PC have 512 MB RAM only. 1GB and above doesn't make a big difference. [source]

Microsoft does have further guidelines on how to use ReadyBoost optimally. It recommends a minimum of a 1:1 ratio of flash to system memory, and that can go as high as 2.5:1.

That means if your system has 1GB of system memory, the smallest size ReadyBoost USB drive you should use would be a 1GB USB drive. The largest would be a USB drive 2.5GB in size, but going beyond the 2.5:1 ratio will not degrade performance.

Outside these limits the system will simply not take advantage of the extra flash memory.

But in Windows 7 things might change a bit.

ReadyBoost works with most flash storage devices. In Windows 7, it can handle more flash memory and even multiple devices—up to eight, for a maximum 256 gigabytes (GB) of additional memory. [source] Meaning you are not limited to one USB anymore. But remember the ratio!