ReadyBoost是Windows操作系统的一个组件，最初在Windows Vista中可用。其目的是帮助SuperFetch服务使您的系统运行更顺畅，通过使用有助于减少对硬盘驱动器的读取和写入次数的快速USB 闪存驱动器。(USB flash)如果您想了解SuperFetch和ReadyBoost是什么以及它们如何协同工作，请不要犹豫，阅读本文。
注意：(NOTE:)本文适用于Windows 7、Windows 8 和 8.1。在这三个操作系统中使用这些技术是相同的。但是，我们使用的屏幕截图是在Windows 8.1中制作的。
SuperFetch 是如何工作的？
SuperFetch是Windows中的一种(Windows)内存管理(memory management)服务，它决定在没有剩余内存时应该将哪些数据从主RAM 内存(RAM memory)传递到硬盘驱动器(disk drive)，而不会降低系统速度。它还存储有关更频繁访问哪些文件和应用程序的信息，并确保在给定时间，所需信息位于随机存取存储器(Random Access Memory)( RAM ) 中，而不是硬盘(Hard Disk)上。SuperFetch从早期版本的Windows中替换了旧的Prefetcher服务(Prefetcher)，它的工作方式非常基本：它缓存了最近使用的文件，因此如果再次访问它们，访问会更快。但是，在系统关闭后，将不会分析以前的活动。SuperFetch还改进了启动时间，因为它在系统启动后学习用户的例程，并且只加载启动时更频繁访问的文件和应用程序，而Prefetcher在启动时是被动的。您应该记住，SuperFetch具有较低的硬盘disk input/output priority，因此它不会减慢使用相同存储设备(storing device)的其他应用程序的速度。
ReadyBoost 是如何工作的？
为了使SuperFetch更高效，ReadyBoost使用快速闪存存储(memory storage)以及计算机上较慢的硬盘存储(disk storage)。我说快，因为不是每个USB 闪存驱动器都与(USB flash)ReadyBoost兼容，只有满足所需性能特征的 USB 闪存驱动器才兼容。快速(Fast)也是相对的，因为闪存具有快速的访问时间，而硬盘在读取顺序数据时更快。SuperFetch使用此信息并将(information and stores)小文件存储在闪存上，同时将大文件加载到硬盘上，最好是在顺序扇区上。
尽管ReadyBoost在(ReadyBoost)RAM较少的系统上有所作为，但它不会将您的USB 闪存(USB flash)驱动器用作额外的随机存取存储器(Random Access Memory)，而是用作更快的存储设备(storage device)。ReadyBoost在具有大量(ReadyBoost)RAM的系统上似乎没有太大帮助的原因是主内存很少被填满，因此硬盘不会被太频繁地访问。知道了这一点，我们就可以理解为什么没有在使用固态硬盘(State Drives)( SSD )的计算机上启用ReadyBoost的原因：它在使用快速存储设备时无法提高性能。
ReadyBoost 技术(ReadyBoost technology)的局限性
ReadyBoost可以使用任何类型的闪存（USB闪存驱动器、SD 卡(SD card)、CompactFlash），其访问时间(access time)为 1 ms 或更短，读取速度至少为 2.5 MB/s s，写入速度至少为 1.75 MB/s。
在Windows 7及更高版本的Windows操作系统中，ReadyBoost最多可以使用 8个USB 闪存(USB flash)驱动器，每个不小于 256 MB，每个最大存储空间为 32 GB(GB storage)，总闪存存储空间为 256 GB。
如果您想了解有关ReadyBoost的更多技术细节，请查看Wikipedia上的此链接。
如何在 Windows 中启用 ReadyBoost
插入(Insert)您要用于ReadyBoost的闪存驱动器并启动文件资源管理器(File Explorer)（在 Windows 8 或 8.1 中）或Windows 资源管理器(Windows Explorer)（在Windows 7中）。在Windows 8和 8.1 中，转至此PC(This PC)部分，您将在其中看到 Windows PC 或设备(PC or device)上可用的所有设备和驱动器。在Windows 7中，转到计算机(Computer)部分。
然后，右键单击或(click or press)按住插入的闪存驱动器以打开上下文菜单。单击(Click)或点击菜单最底部的属性。(Properties)
如果您想在Windows 8和 8.1 中使用功能区，请在选择您插入的可移动驱动器后转到“计算机”选项卡。然后。(Computer)单击或点击(click or tap) 位置(Location)部分中的属性。(Properties)
为选择的可移动驱动器打开“属性(Properties)”窗口。
在这里，您可以更改有关此驱动器的许多设置。要访问ReadyBoost相关选项，请单击或点击ReadyBoost选项卡。
如果您的闪存驱动器(flash drive)是第一次插入，操作系统(operating system)将首先测试它是否足够快以供ReadyBoost使用。
如果此驱动器与ReadyBoost(ReadyBoost)不兼容，则会显示一条消息，说明您的设备无法使用ReadyBoost的原因以及设备上次测试的时间。如果您认为之前的测试结果不正确，您也可以再次测试闪存驱动器，方法是单击或点击(flash drive)再次测试(Test again)。
如果您有一台速度非常快的PC 或设备(PC or device)，您很可能会看到一条消息说“未启用 ReadyBoost，因为这台计算机足够快，ReadyBoost 不太可能提供额外的好处”("ReadyBoost is not enabled because this computer is fast enough that ReadyBoost is unlikely to provide additional benefit")。
如果您的闪存驱动器(flash drive)兼容并且您的 PC 可以从使用ReadyBoost中受益，您将获得 3 个在此驱动器上使用它的选项。
当设备尚未使用ReadyBoost时，(ReadyBoost)默认选项(default option)是“不使用此设备”("Do not use this device")。可以想象，此选项用于关闭ReadyBoost的使用。
要开启ReadyBoost，您可以选择：
“将此设备专用于 ReadyBoost”("Dedicate this device to ReadyBoost") - 闪存驱动器的全部剩余存储容量(storage capacity)都充满了缓存文件。
“使用此设备” - 您可以选择您希望("Use this device")ReadyBoost在此设备上使用多少存储空间，方法是使用下面的滑块或在相应的框中键入您要使用的内存量。请(Please)记住，您不能总是将设备上的所有存储空间都用于ReadyBoost，因为也有闪存驱动器同时包含慢速和快速内存，因此只能使用设备的快速部分。
做出选择后，单击或点击(click or tap) 确定(OK)并等待ReadyBoost配置您的缓存。
ReadyBoost现在使用您的设备。如果您打开闪存驱动器，您将看到缓存文件被压缩到ReadyBoost.sfcache文件中，该文件具有您在配置(ReadyBoost.sfcache)ReadyBoost时选择的大小。您可以像使用任何其他设备一样使用ReadyBoost闪存驱动器，如果您有足够的空间，您仍然可以在其上复制文件，或者您可以删除任何文件，系统当前使用的ReadyBoost.sfcache文件除外。(ReadyBoost.sfcache)
如果您在ReadyBoost(ReadyBoost)使用设备时弹出设备，则不会发生错误，因为闪存驱动器仅用于安全文件。可能发生的最糟糕的事情是您的系统将再次变慢。但是，当您再次插入闪存驱动器时， ReadyBoost(ReadyBoost)仍将使用它，并使用上次ReadyBoost配置您的设备时使用的设置。
如何禁用 ReadyBoost？
如果您不想让ReadyBoost再使用您的设备，您必须再次打开“属性(Properties)”窗口。
转到ReadyBoost选项卡，单击或点按“不使用此设备”("Do not use this device")，然后单击或点按确定(OK)。
ReadyBoost再次配置您的缓存，无需您的闪存驱动器(flash drive)即可工作。完成后，该驱动器看起来就像任何其他可移动存储设备(storage device)一样。
结论
ReadyBoost首次在Windows Vista中提供时非常有用，因为当时硬盘比现在慢，并且(today and systems)RAM超过 1GB 的系统并不常见。今天，大多数硬盘的速度足以跟上系统的其余部分，即使对于价格实惠的 PC 或设备，4GB 的RAM也是标准配置。ReadyBoost不会对这些系统产生巨大影响。但是，如果您使用的是旧设备，您仍然可以使用ReadyBoost来让您的系统运行得更快一些。
What are ReadyBoost & SuperFetch? How to Use Them in Windows
ReadyBoost is a component of Windows operating systems, that was first available in Windows Vista. Its purpose is to help the SuperFetch service in making your system run smoother, by using a fast USB flash drive that helps reduce number of read and writes to your hard drive. If you would like to learn what SuperFetch and ReadyBoost are and how they work together, don't hesitate to read this article.
NOTE: This article applies to Windows 7, Windows 8 and 8.1. Using with these technologies is the same in these three operating systems. However, the screenshots we used were made in Windows 8.1.
How does SuperFetch works?
SuperFetch is one of memory management services found in Windows, that decides what data should be passed from the main RAM memory to the hard disk drive when there is no memory left, without slowing down the system. It also stores information about what files and applications are accessed more often and makes sure that, at a given time, the required information is located into the Random Access Memory (RAM) rather than on the Hard Disk. SuperFetch replaced the old Prefetcher service from earlier versions of Windows, which was pretty basic in the way it worked: it cached files that were used more recently, so if they were accessed again, the access would be quicker. However, after the system was turned off, previous activity would not be analysed. SuperFetch also improves boot times because it learns the user's routine after the system is powered on and loads only the files and applications that are accessed more often on startup, while Prefetcher was passive on boot. You should keep in mind that SuperFetch has low hard disk input/output priority, so it will not slow down other applications using the same storing device.
How does ReadyBoost works?
In order to make SuperFetch more efficient, ReadyBoost uses fast flash memory storage in addition to the slower hard disk storage available on your computer. I say fast, because not every USB flash drive is compatible with ReadyBoost, only the ones that meet the required performance characteristics. Fast is also relative, because flash memory has fast access times while hard disks are faster when reading sequential data. SuperFetch uses this information and stores small files on the flash memory, while loading the large files on the hard disk, ideally on sequential sectors.
Despite the fact ReadyBoost makes a difference on systems with low amounts of RAM, it doesn't use your USB flash drive as additional Random Access Memory, but as a faster storage device. The reason ReadyBoost does not seem to help very much on systems with large amounts of RAM is that the main memory is rarely full, so the hard disk is not accessed too often. Knowing that, we can understand the reason why ReadyBoost is not enabled on computers using Solid State Drives (SSD): it can't improve performance when using fast storage devices.
The limitations of the ReadyBoost technology
ReadyBoost can use any type of flash memory (USB flash drive, SD card, CompactFlash) that has an access time of 1 ms or less and at least 2.5 MB/s in read speed and 1.75 MB/s in write speed.
In Windows 7 and later Windows operating systems, ReadyBoost can use up to 8 USB flash drives, not smaller than 256 MB each, with a maximum of 32 GB storage each and a total flash storage of 256 GB.
If you want to learn more technical details about ReadyBoost, please check this link on Wikipedia.
How to enable ReadyBoost in Windows
Insert the flash drive you want to use for ReadyBoost and start File Explorer (in Windows 8 or 8.1) or Windows Explorer (in Windows 7). In Windows 8 and 8.1, go to the This PC section, where you will see all the devices and drives that are available on your Windows PC or device. In Windows 7, go to the Computer section.
Then, right - click or press and hold the plugged in flash drive to open the contextual menu. Click or tap Properties, at the very bottom of the menu.
If you would like to use the ribbon in Windows 8 and 8.1, go to the Computer tab after selecting the removable drive you plugged in. Then. click or tap Properties in the Location section.
The Properties window opens for the select removable drive.
Here you can change lots of settings regarding this drive. To get to the ReadyBoost related options click or tap the ReadyBoost tab.
If your flash drive was inserted for the first time, the operating system will first test whether it is fast enough to be used by ReadyBoost or not.
If this drive is not compatible with ReadyBoost, a message is displayed, sharing the reason why your device cannot work with ReadyBoost and the last time the device was tested. You can also test the flash drive again, if you think the previous test's results are not correct, by clicking or tapping Test again.
If you have a very fast PC or device, it is very likely that you will see a message saying that "ReadyBoost is not enabled because this computer is fast enough that ReadyBoost is unlikely to provide additional benefit".
If your flash drive is compatible and your PC can benefit from using ReadyBoost, you get 3 options for using it on this drive.
The default option when the device is not already used ReadyBoost, is "Do not use this device". As you can imagine, this option is for turning off the use of ReadyBoost.
To turn on ReadyBoost, you can choose:
"Dedicate this device to ReadyBoost" - the entire remaining storage capacity of your flash drive is filled with cached files.
"Use this device" - you can choose how much storage you want ReadyBoost to use on this device, by using the slider below or by typing the amount of memory you want to use, in the corresponding box. Please keep in mind that you can't always use all the storage on your device for ReadyBoost, because there are also flash drives that contain both slow and fast memory, so only the fast part of your device can be used.
After you have made your choice, click or tap OK and wait until ReadyBoost configures your cache.
You device is now used by ReadyBoost. If you open your flash drive, you will see that the cached files are compressed into the ReadyBoost.sfcache file, that has the size you selected when you configured ReadyBoost. You can use your ReadyBoost flash drive just like any other device, you can still copy files on it if you have enough space left or you can delete any files, except the ReadyBoost.sfcache file that is currently used by your system.
If you eject your device when it is used by ReadyBoost, no errors will occur because the flash drive is only used for safe files. The worst thing can happen is that your system will become slow again. However, when you insert your flash drive again, it will still be used by ReadyBoost, with the settings used the last time ReadyBoost configured your device.
How to disable ReadyBoost?
If you don't want ReadyBoost to use your device anymore, you have to open the Properties window again.
Go to the ReadyBoost tab, click or tap "Do not use this device", then click or tap OK.
ReadyBoost configures your cache again, to work without your flash drive. When done, the drive will look just like any other removable storage device.
Conclusion
ReadyBoost was very useful when it was first made available in Windows Vista because, at that time, hard disks were slower than today and systems with more than 1GB of RAM were not that common. Today, most hard disks are fast enough to keep up with the rest of the system and 4GB of RAM is the norm even for affordable PCs or device. ReadyBoost won't make a huge difference on these systems. However, if you are using an older device, you can still use ReadyBoost to make your system run a bit faster.
