Windows 7: Optimizing Performance (part 3) - Using ReadyBoost to Enhance Performance

5. Using ReadyBoost to Enhance Performance

Windows 7 uses your computer’s disk drives for paging files and system cache. Because reading from and writing to a disk is significantly slower than reading from and writing to physical memory (RAM), this can cause performance bottlenecks that make your computer seem sluggish or unresponsive. To reduce the performance impact related to reading and writing the system cache, Windows 7 introduces Windows ReadyBoost.

Windows ReadyBoost is a feature that lets you extend the disk-caching capabilities of the computer’s main memory to a USB flash device. Using flash devices for caching allows the operating system to make random reads faster by caching data on the USB flash device instead of your computer’s disk drives. Windows 7 can read flash devices up to 1,000 percent faster than physical disk drives, significantly boosting the overall performance of your computer.

The types of USB flash devices you can use with Windows ReadyBoost include:

• USB 2.0 flash drives

• Secure Digital (SD) cards

• CompactFlash cards

Further, these devices must be at least 256 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. You can reserve from 230 MB to 4,094 MB of flash memory for ReadyBoost. I recommend using from one to three times the installed RAM memory. On a system with more than 4 GB of memory, you will only be able to reserve a fractional amount as compared to the available memory. Currently, 4GB is the limit (but this limit may change as high performance USB flash drives and 64-bit computers become increasingly prevalent).

When Windows ReadyBoost is enabled, Windows 7 uses the USB flash device primarily for caching that uses random input/output and small, sequential input/output 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 7 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 7 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 7 encrypts all data written to a flash device so that it can be used only with the computer on which it was originally written.

5.1. 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. If your computer has an SD, CompactFlash, or similar card slot, you can insert a supported flash device into that slot.

2. The AutoPlay dialog box should be displayed automatically.

NOTE

Windows 7 should display the AutoPlay dialog box automatically. If it doesn’t, you’ve probably selected the “Always do this...” checkbox 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.

1. If the flash memory performs at a sufficiently high speed, Windows 7 will display a “Speed up my computer” option in the AutoPlay dialog box. (If you always want to use the device with Windows ReadyBoost when inserted, select the “Always do this...” checkbox.) When you click “Speed up my system using Windows ReadyBoost,” the device’s Properties dialog box is opened to the ReadyBoost page, as shown in Figure 3-22. Do one of the following and then click OK:

   • If you want the device to automatically reserve the maximum amount of space for ReadyBoost, select “Dedicate this device to ReadyBoost.” Choosing this setting option doesn’t prevent you from writing files to the device. It simply configures ReadyBoost to use as much space as can be reserved.

   • If you want to use less space with ReadyBoost than the maximum possible, select “Use this device” and then use the “Space to reserve for system speed” slider or combo box to set the amount of space to use with ReadyBoost. If you reserve less than the total amount of space available, the free space can be used for files and data.

2. When you click OK, Windows 7 extends the computer’s physical memory to the device.

Figure 5. Configuring Windows ReadyBoost

If you previously inserted a flash device and declined to use Windows ReadyBoost, you can enable ReadyBoost by completing the following steps:

1. Click Start and then click Computer.

2. Right-click the USB flash device in the Devices with Removable Storage list and then choose Properties.

3. On the ReadyBoost tab, configure the options as discussed previously. For devices that don’t support ReadyBoost, you cannot enable the device and the “Stop retesting this device when I plug it in” option is selected by default. If you want Windows to retest the device, unselect this checkbox.

4. Click OK.

5.2. Configuring Windows ReadyBoost

Windows ReadyBoost does not have to use all available space on the USB flash device. You can also configure a specific amount of space to reserve for files and data. To do this, complete the following steps:

1. Click Start and then click Computer.

2. Right-click the USB flash device in the “Devices with removable storage” list and then choose Properties.

3. Click the ReadyBoost tab, as shown in Figure 3-22.

4. Use the “Space to reserve for system speed” slider or combo box to set the amount of space to use with ReadyBoost.

5. Click OK.

5.3. Ejecting a ReadyBoost device

You can safely remove a USB flash device that uses ReadyBoost at any time. Because Windows 7 writes to disk first and then copies data to the device, no data is lost and there is no negative impact on your computer. However, when you remove the device, your computer’s performance level returns to its normal, nonboosted state. You can safely remove a USB flash device by completing these steps:

1. Click Start and then click Computer.

2. Right-click the USB flash device in the “Devices with removable storage” list and then choose Eject or Safely Remove.