Chapter 3: Fine-Tuning Windows Vista’s Appearance and Performance
Further, these devices must be at least 512 MB or larger and have sufficiently fast
flash memory. Because some flash devices have both slow and fast memory, you may
find that Windows ReadyBoost can use only a portion of the memory on the device.
Windows Vista can use an amount of flash memory equal to twice the amount of
physical memory (RAM) on the computer. Therefore, if your computer has 1 GB of
RAM, you could use up to 2 GB of memory on a flash device to boost your com-
When Windows ReadyBoost is enabled, Windows Vista uses the USB flash device
primarily for caching that uses random input/output and small, sequential input/out-
put rather than large, sequential input/output. This is because the memory on USB
flash devices is better suited to random I/O and small, sequential input/output than
large, sequential I/O.
Because USB flash devices are meant to be portable, Windows Vista adds protections
to prevent the sudden removal of a USB flash device from crashing the computer and
to prevent reading of any sensitive data written to the flash device. To allow a USB
flash device to be removed at any time, Windows Vista ensures that all data writes are
made to the hard disk first and then copied to the flash device. This eliminates the
potential for data loss when removing a flash device. To prevent reading of sensitive
data, Windows Vista encrypts all data written to a flash device so that it can be used
only with the computer on which it was originally written.
Enabling Windows ReadyBoost
You can enable Windows ReadyBoost by completing the following steps:
1. Insert a USB flash device into a USB 2.0 or higher port.
2. The AutoPlay dialog box should be displayed automatically. If you always want
to use the device with Windows ReadyBoost when inserted, select the “Always
do this...” checkbox.
Windows Vista should display the AutoPlay dialog box automatically.
If it doesn’t, you’ve probably selected the “Always do this...” check-
box previously. You can clear a previous selection by clicking Start
Default Programs. On the Default Programs page in the Control Panel,
click “Change AutoPlay settings.” On the AutoPlay page, scroll down
to the bottom of the page. Click “Reset all defaults” and then click
Save. Remove the USB flash device and then reinsert it to display the
AutoPlay dialog box.
3. If the flash memory performs at a sufficiently high speed, Windows Vista will
display a “Speed up my computer” option in the AutoPlay dialog box. Select the
“Speed up my system using Windows ReadyBoost” option.
4. Windows Vista extends the computer’s physical memory to the device. The
default configuration enables Windows ReadyBoost to reserve all available space
on the device for boosting system speed.