Lesson 1: Troubleshooting Performance Issues

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Implementing ReadyBoost

ReadyBoost uses spare space on USB-based storage devices—flash memory, for example—to

improve computer performance. It does this by caching information to the USB device, which

is typically faster than writing to a swap file on the hard disk drive. Information cached to the

device is encrypted, so it cannot be read on other systems. The memory must be fast flash, and

the computer needs a USB 2.0 port.

Swap File

A swap file is hard disk space used to extend RAM, and it allows your computer’s OS to

operate as if the computer has more RAM than it actually does. The least recently used

files in RAM can be swapped out, or paged, to your hard disk until they are needed later

and new files can be paged into RAM.

An advantage of a swap file is that it can be organized as a single contiguous space so that

fewer input/output (I/O) operations are required to read or write a complete file. The

disadvantage is that it takes time for a standard hard disk to access virtual memory. If a

computer’s memory is not sufficient for a memory-intensive operation, this can lead to

excessive paging to hard disk and a consequent drop in performance.

Windows Vista (and other Windows OSs) provides a swap file, known as virtual mem-

ory, with default initial and maximum sizes. An administrator can reconfigure virtual

memory size. The swap file is also known as the page file or paging file.

Configuring a Flash Memory Device for ReadyBoost

The user inserts a suitable flash memory device (typically, but not necessarily, a USB device)

into a Windows Vista computer. The Autoplay dialog box appears, giving the user the option

either to use the device to store files or to speed up the system. On choosing the second

option, the user then needs to specify, in the ReadyBoost tab of the device’s Properties dialog

box, that Windows Vista should use the device for this purpose and how much flash memory

it should allocate. By default, Windows Vista allocates 95 percent of free space on a flash mem-

ory device for ReadyBoost. Microsoft recommends configuring ReadyBoost with one to three

times the amount of RAM that is installed in the system. So if a computer has 512 MB of RAM,

the user should dedicate between 512 MB and 1.5 gigabytes (GB) of space for ReadyBoost.

ReadyBoost recommends the ideal amount, based on the capacity of the device and the sys-

tem’s RAM. You enable ReadyBoost in the practice session later in this lesson.