Windows 7 has ReadyBoost feature which uses USB Flash Drive as an external hard disk cache, it improves optimal performance of PC or Laptop. If your PC or Laptop is using SSD (Solid State Drive) as a primary disk your machine will not give you performance improvement, however the ReadyBoost will be disabled automatically. ReadyBoost supports specific type of external disk drives i.e. USB Memory Sticks, SD Cards and CF Cards.
There are some requirements which must meet with these conditions:
- At least 256 MB capacity and at least 64 kilobytes (KB) of free space on external drive.
- (The limit of 4-GB in Windows Vista has been removed)
- The best way to check if your external drive compatible with ReadyBoost or not is to test it, when you will attach any compatible removable drive with Windows Vista or 7, the system will automatically test it.
- If external drive isn’t compatible with system, your Windows will repeatedly fail the test.
On the other hand, to configure ReadyBoost open Windows Explorer / My Computer then Right-Click on external drive > Properties and then select ReadyBoost tab. Here you need to organize the reserved space for cache. The minimum requirement of space to reserve for system speed is 256 MB, the more space you reserve for system cache, the faster speed you gain. If you are using external drive with FAT32 file system, it should not be larger than 4GB reserved space to use ReadyBoost and if the file system is NTFS, it should not be larger than 32 GB.
Most of the time a message appears on your Computer screen after connecting the external drive that is “Enhanced for Windows ReadyBoost”, it means that Microsoft has specifically tested the external device for this feature. After connecting certain Flash Drives with system an AutoPlay option appears automatically which means that the device meets the feature requirements.
Windows SuperFetch Algorithm decides which file is needed to be stored in system cache while using Windows 7. It monitors user files together with Application files, Documents and System files and then prepares those files in ReadyBoost cache. In cache, if Flash drive is a removable device then all files would be encrypted in 128-bit AES format. But hardware manufacturer can disable encrypt option on non-removable ReadyBoost devices. The flash drive can be removed anytime without effecting on machine’s performance, because the ReadyBoost cache saves necessary files on flash drive. And after the drive is removed, Windows can read original files directly from the system disk.
There are some circumstances which ReadyBoost is needed to improve performance significantly:
- Machine with slower hard disk drive and a primary hard disk with less than 4.0 sub-scores in Windows Experience Index (WEI) can see noteworthy improvements.
- Fast, Random and Non-Sequential reads are being provided by the flash storage. Sequential read speed is not much essential.
If you are using memory cards for this purpose and using card readers to connect memory card with system then, I must recommend you to use built in memory card readers to feel the performance improvement difference. External USB Card readers are less trustworthy.
In the root of flash drive disk the ReadyBoost feature creates a file which name is ReadyBoost.sfcache. For the complete size of the particular cache this file is created immediately. Though, Windows regularly fill the space with cached files.
If you want to observe the performance with ReadyBoost cache, Windows provide you a performance monitor tool which is located in Computer Management > System Tools > Performance > Monitoring Tools > Performance Monitor.
Now click on performance monitor and add the ReadyBoost cache counters. These counters are used to observe amount of cache which is currently being used and notify you when the cache is read/write, but also it will not let you know the overall performance and benefit achieved by the ReadyBoost.