Facts and tips about optimization using “Prefetch” and “Superfetch” in Windows XP™ and Vista™.Windows anticipates your needs. The two functions Prefetch and Superfetch make sure your programs start quickly when you open them. This means it no longer takes an eternity for the program window to appear. But beware – rumors and false tips have been circulating the Internet for years.
The truth about Prefetch and Superfetch!
New to Windows XP™, Microsoft introduced the Prefetch component. It remembers which file segments a program reads into memory once an application has been started. If the user, for example, double-clicks on the link to Microsoft Word, a large number of files are read into memory in the background, even though usually only certain segments of these files are actually needed to start the program. This makes the hard drive’s reading head jump from file to file in order to collect all of the necessary information. This takes time and leads to considerable delays in starting the program!
“Prefetch” remembers these segments and stores them in a file in the folder “WindowsPrefetch”. By clicking on Microsoft Word, users now save time since those files and data needed to start the program have already been preloaded.The “Superfetch” technology in Windows Vista™ also speeds up loading times for applications. It "learns" over time which programs users run most often. For example, if you frequently start the Media Player and Firefox after switching on the computer, Superfetch preloads the data needed to run these applications into your system memory. This means, your programs will be ready whenever you need them, because now the significantly slower hard drive no longer has to do the work!
Unfortunately there are a lot of false tips and information about Prefetch and Superfetch on the Internet. Even reputable online magazines and trade magazines sometimes erroneously publish this information, thereby causing even more confusion. If you are lucky, these myths about optimization will have no effect on your PC. More often than not, however, they even slow down system performance!
Keep away from the Prefetch folder!
Emptying this folder immediately slows down run times until Windows has once again compiled all required Prefetch information and this is a long and slow process. Windows automatically cleans up the folder.Prefetch does not use up memory unnecessarily. Disabling it actually increases loading times for programs.Superfetch preloads those applications into memory that are used most. However this is only happens if Windows does not execute any other write or read accesses. Disabling Superfetch therefore does not affect the time it takes to launch Windows.
What’s more, disabling Superfetch does not save memory.
By doing so, memory remains unused and empty – a true waste of your computer’s resources! It is therefore better for Superfetch to fill the memory with this data thereby improving your system’s performance. Please note: If a program is started that is not immediately recognized by Superfetch, this does not mean that there is no memory available to run this program. Windows empties a portion of the memory used by Superfetch within a few milliseconds so that the program can immediately use it.
TuneUp Utilities 2009 users can sit back and relax, since TuneUp Speed Optimizer detects incorrect settings for Prefetch and Superfetch. Follow these steps for quicker loading times on a sustained basis:
Start TuneUp Utilities 2009. Go to the Start page and under “System health”, click on “Details”, if problems have been indicated in this area. If not, move on to the next step.
Now go through the individual problems. If the message “Prefetch data deleted” appears, either you or a program has emptied the folder with the important Prefetch data. If this is the case, make sure that the data can no longer be deleted.Switch to “Increase performance” in TuneUp Utilities 2009. Then click on “TuneUp Speed Optimizer”. If TuneUp Speed Optimizer is being started for the first time you will first be required to answer four questions. Confirm the selected settings with “OK” and then click on “Quick Optimization”.
In order to use these functions effectively, you need to defragment the hard drive. This ensures that Prefetch data are optimally positioned on the hard drive so that they can be accessed more quickly.
Sources and Citations: : Windows myths exposed! TuneUp Utilities newsletter