XP prefetch

What is prefetch. is it needed for the operation of windows XP. And what is the effect of enabling/disabling it. Thanks

 

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Windows XP Prefetch
This is a unique technique for Windows XP operating system. Following is a definition given by Microsoft on prefetching technique.

Windows XP monitors the files that are used when computer starts and also when you start applications. By monitoring these files, Windows XP can prefetch them. Prefetching data is the process whereby data that is expected to be requested is read ahead into the cache. Prefetching boot files and applications decreases the time needed to start Windows XP and start applications.

This information is logged and stored on your hard drive taking up space and requires a process to be kept running monitoring which applications are being run often. This has a performance impact on your PC. Disabling the prefetch function or at least only enabling it for the boot files will allow you to freee up some system resources and preserve some disk space.

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see more at this link

http://forum.gladiator-antivirus.com/index.php?showtopic=10667&hl=xpantispy

Posted there you will also see a free small tool called

Windows XP Prefetch Clean And Control

with screenshots giving you 3 ways to handle the situation.

 

Now for an indepth look at the Prefetch in WinXP..



From:
Alex Nichol MS MVP


When a program is loaded, a record is put, or updated, in the corresponding file in Prefetch, detailing what files it uses, in what order. Boot of the system has such a record, too

From that two things happen.

One - when a load is started in future, the system arranges to get the expected files into RAM straight away, without waiting to be asked, and

Two - every three days, a sort of semi-defrag run is done in a quiet period, which arranges files so that such sets will be able to load as a smooth stream without need to hunt around the disk for them. The boot side of this speeds load of the system: the Bootvis program does a preliminary optimisation of their layout, but it will take place, and better, through the automatic process. The details of the best layout are kept in the layout,inf file which is checked and updated each time this optimisation runs, for the best overall performance. This can be used for optimisation alternatively by some third party defrag programs, eg Perfect Disk Pro

Two points:

Contrary to what is said (most recently I notice in Fred Langa's Langa list), it is *not* necessary to empty prefetch. Any program that does not get used for a week will have its file dropped out anyway: ones that are rarely used get low priority in optimisation

and: The optimisation at regular intervals is initiated by task scheduler so you need to have it running for this to work (also for System Restore to make its daily restore point) even though no scheduled task appears if you look in control Panel - Scheduled tasks. Check the Advanced menu there, and if it says 'Start Using. . ' click that so it says 'Stop using . . .' It then looks for a time when the system is quiescent (I think it waits for 15 mins of no disk activity, but am not sure on that). This is one reason for the query 'my hard disk goes chattering when I am doing nothing'; the other being search engine indexing.

--
Alex Nichol MS MVP (Windows Technologies)
Bournemouth, U.K.
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&client=googlet&threadm=tprrmvslb97fj8o8vbodguje81qllof1q0%404ax.com&rnum=9&prev=/groups%3Fq%3DXP%2Bprefetch%2B%26hl%3Den%26lr%3D%26ie%3DUTF-8%26client%3Dgooglet%26sa%3DN%26tab%3Dwg





And if you want some detailed tech info from Microsoft to read on it:



These may help.
http://msdn.microsoft.com/msdnmag/issues/01/12/XPKernel/default.aspx

http://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/winxppro/evaluate/xpperf.asp


http://www.microsoft.com/whdc/hwdev/driver/xp_kernel.mspx

 

If you would like a program to control the prefetch by emptying it or shutting it down there is a free one at the link it works very well. I have had my prefetch shut off for almost a year and it causes my computer to boot faster.


http://www.majorgeeks.com/download2495.html


Tool for flushing the Prefetch log and controlling the Prefetch Parameters.

What Is Prefetch?

Taken From Microsoft Website:

Windows XP monitors the files that are used when the computer starts and when you start applications. By monitoring these files, Windows XP can prefetch them. Prefetching data is the process whereby data that is expected to be requested is read ahead into the cache. Prefetching boot files and applications decreases the time needed to start Windows XP and start applications.

This information is logged and stored on your hard drive taking up space and requiring a process to be kept running monitoring which applications are being run. This has a performance impact on your PC. Disabling the Prefetch function or at least only enabling it for the Boot Files will allow you to free up some system resources and preserve some disk

 

Thank you all
Thank you bigc73542
for this little handy tool, no need to tweak the registry.

 

Any one please
(may be bigc73542)
know by any chance a tool or a tweak to empty"temp"
C:/document and settings7your login name/local settings/temp
on shutdown or on restart. Thanks for helping

 

I would like to help you, I looked but i don't have a temp folder there. I have a customized version of xp pro and a few things are different than xp home or pro. but I will look to see if I can find something that will do the trick for you.

 

Thank you bigc73542

I found this small (667Kb) but effective program and it is 4 free
You can set it to clean IE history, cookies, URLs, internet temporary files, prefetch folder, temp folders and much more in just one click

http://www.danish-shareware.dk/soft/emptemp/