Win7 feature allows U disk to act as system cache

In the computer system, the speed of the hardware is basically determined by the cache, the larger the capacity of the cache, the corresponding hardware to run faster. For many users of the old computer, and do not want to spend money to speed up friends may wish to try to make your USB disk into the system cache it. As long as you have idle u disk, we can take advantage of Windows 7 ReadyBoost function, the U disk as a system cache disk, although the U disk speed is far less than memory, or even sequential read speed than hard disk, but U disk has a feature, that is, has a strong random read performance, This is a good carrier for caching.

ReadyBoost a service and a volume filter driver (%systemroot%system32driversecache.sys) that is running in the host process implemented in%systemroot%system32emdmgmt.dll Composition When the flash device is plugged into the system, the ReadyBoost service looks at the device to determine its performance characteristics and stores the test results in the HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindows In Ntcurrentversionemdmgmt.

Not all flash devices can support the ReadyBoost feature, wrote in Microsoft's technical documentation: "When the capacity of a flash device is between 256MB and 32GB, the transmission rate for 4KB random reads is 2.5MBPS or higher, When the transfer rate of 512KB random writes is 1.75MBps or higher, ReadyBoost will ask the user if they want to use some of the storage space for disk caching.

Although ReadyBoost can use NTFS, it will limit the maximum cache size to 4GB to accommodate the FAT32 limit. If the user agrees to use the ReadyBoost feature, the service creates a cached file named Readyboost.sfcache in the root directory of the device and requires SuperFetch to populate the cache in the background.

After the ReadyBoost service initializes the cache, the Ecache.sys device driver intercepts all read and write data to the local hard disk volume (for example, C:) and copies all the data that will be written to the cache file created by the service. Ecache.sys will compress the data, and the compression ratio usually reaches 2:1. In this way, 4GB of cached files will typically contain 8GB data. The driver uses a combination of Advanced Encryption Standard (AES) and a randomly generated boot session key to encrypt each block it writes to guarantee the confidentiality of the data in the cache when the device is removed from the system.

When ReadyBoost determines that the cache in the flash memory is more responsive to random read requirements than the cache inside the hard disk, it randomly reads the data from the Flash disk media. The hard drive's ordered read access is significantly better than flash memory, so when ReadyBoost detects that a system is using ordered access to data, it will read directly from the disk, even if the data is also in the cache within the Flash disk media.

It is based on this principle that ReadyBoost can act as a bridge between memory and hard disk, thus accelerating system performance. The specific actions are as follows:

1, first we insert U disk, and then in the computer, right click on the U disk icon, select "Properties" and switch to the ReadyBoost icon:

2. Select the second or third item to turn on the ReadyBoost function.

After using ReadyBoost, small series of 1TB mechanical hard drive, the original score is 5.9 points, now the score soared to 7.3 points

It is worth mentioning that, ReadyBoost is not the high-end features in Windows 7, in the family based on the focus of this feature, this is not the determination to buy a genuine? If you're not clear, here we can specify that Windows 7 of the home base version in the domestic price of only 399 yuan, a very low price, and, at this price, you can use the ReadyBoost function to speed up the system, with your idle disk to improve the system speed.

If your system is configured with less than 2GB of memory, the acceleration effect will be very obvious, if you have more than 2GB of memory, you will get a certain degree of acceleration, which is more than spending money to buy a thousands of-yuan solid-state hard drive more cost-effective, so the genuine Windows 7 is essential, first, the price is cheap, secondly, ReadyBoost is a technical content of a very high functional characteristics, piracy system is often prone to instability, which let our users outweigh the gains, if not to accelerate but harvest the blue screen crash or let U disk damage, which is contrary to our original intention of optimization.