There’s no such thing as a fast-enough computer. No matter how hot your CPU runs or how much RAM you have, eventually you’ll run out of performance — usually, just when you need it most. Fortunately, Windows 7 comes with a cheap and easy way of improving system performance: ReadyBoost.
Windows 7’s ReadyBoost is Microsoft’s latest take on a very old idea for improving computer performance: caching. With a cache, you gain speed by keeping frequently accessed data as close as possible to the CPU cores. The faster the cache, the closer it should be to cores. That’s why high-end processors, like the Intel i7 quad-core CPU, have their own on-board cache.
Caching used to be easy. You used caching on uniprocessor, single user systems to free yourself from the slow I/O jail, whether that I/O was from the system bus to the processor or from the hard drive to the bus. As multiple-CPU and core systems became more common, simply placing fast RAM between system components with varying I/O throughputs was no longer enough. System designers had to contend with making sure that the available data to the processor was the real, newest data.
In ReadyBoost, cached data is stored in a Flash memory drive (usually a USB stick, but Secure Digital (SD) and Compact Flash (CF) cards are also supported). When data is read at random rather than in large blocks of data, ReadyBoost can improve file and data read input/output (I/O) by several times over traditional hard drives. You also get a performance boost from random writes, but it won’t be as significant.