[fleamailman]

Ok, I am chatting with Joe Duncehead, elsewhere and he keeps saying that deleting the prefetch is a waste of time whereas I know it to be part of our standard clean up here, I want to have in my mind an exaact idea why deleting the prefetch enties isQuote:

Originally Posted by fleamailman
The idea is just to delete all the entries in that folder which are preperations to programs that wildow creates and stores for future use, trouble is that their number build up and cause conflict and nothing is lost when you delete them because if window doesn't find one it just makes one for next time. Important you are deleting everrthing in the folder not the folder itself.

His opinion then
"Preperations" - Is this a new Technical term?
The number of files here do NOT build up and they do NOT cause conflicts. And, yes something IS lost. These files are not just built once, but rather fine tuned every time that particular program is executed. So, by deleting the files you are losing the fine tuning.
a good thing and why not doing it is a bad thing.

I am not the type to go back and have it out but I would like to know how things stand in case this response was ever muted here. Thanks then.

Edited by fleamailman, 15 April 2006 - 01:42 PM.

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Hi Fleamailman...

In Computer architecture, instruction prefetch is a common technique used in modern microprocessors to speed up the execution of a program by reducing wait states.

Modern microprocessors are much faster than the memory where the program is kept. This means that, literally, the program's instructions cannot be read fast enough to keep the microprocessor busy (see CPU cache for a common workaround).

Prefetch is the processor action of getting an instruction from the memory well before it will need it. In this way, the processor will not need to wait for the memory to answer its request.

The prefetched instruction may simply be the next instruction in the program, fetched while the current instruction is being executed. Or, the prefetch may be part of a complex branch prediction algorithm, where the processor tries to anticipate the result of some calculation and fetch the right instructions in advance. In the case of dedicated hardware (like a Graphics Processing Unit, or GPU, for example) the prefetch can take advantage of the spatial coherence usually found in the texture mapping process. In this case, the prefetched data are not instructions, but texture elements (texels) that are candidates to be mapped on a polygon.

Ok...that being the case, what if one of the prefetch instructions becomes corrupt? The processor is going to be trying to use a bad instruction which may have quite adverse effects on the process or application being loaded. Clearing the Prefetch and rebooting repopulates the folder with fresh, good instructions for the processor to use while waiting for the memory to "catch up".

wannabe1

[wannabe1]

Hi Fleamailman...

In Computer architecture, instruction prefetch is a common technique used in modern microprocessors to speed up the execution of a program by reducing wait states.

Modern microprocessors are much faster than the memory where the program is kept. This means that, literally, the program's instructions cannot be read fast enough to keep the microprocessor busy (see CPU cache for a common workaround).

Prefetch is the processor action of getting an instruction from the memory well before it will need it. In this way, the processor will not need to wait for the memory to answer its request.

The prefetched instruction may simply be the next instruction in the program, fetched while the current instruction is being executed. Or, the prefetch may be part of a complex branch prediction algorithm, where the processor tries to anticipate the result of some calculation and fetch the right instructions in advance. In the case of dedicated hardware (like a Graphics Processing Unit, or GPU, for example) the prefetch can take advantage of the spatial coherence usually found in the texture mapping process. In this case, the prefetched data are not instructions, but texture elements (texels) that are candidates to be mapped on a polygon.

Ok...that being the case, what if one of the prefetch instructions becomes corrupt? The processor is going to be trying to use a bad instruction which may have quite adverse effects on the process or application being loaded. Clearing the Prefetch and rebooting repopulates the folder with fresh, good instructions for the processor to use while waiting for the memory to "catch up".

wannabe1

[fleamailman]

Wanabe 1, I really want to thank you for your effort here, not only do I feel vindicated, I have clearly learned something for the next time I am quiried on it,
sin.,
flea

[wannabe1]

You're welcome flea!

[fleamailman]

Today too I got this posted back to me, think he means well but don't know how to form, in my mind only at least, a counter arguement


prefetch

What it is.
http://www.extremete...,1148808,00.asp

In relation to defrag
http://support.micro...1&Product=winxp

why it is bad one
http://poptech.blogs...ation-load.html

why it is bad two
http://www.edbott.co...ves/000743.html

Edited by fleamailman, 16 April 2006 - 11:07 AM.

[Retired Tech]

The drawback to prefetching is that XP will prefetch a program even if you use it only once or twice. XP will retain a copy of a portion of it in the Prefetch folder. From there, it will prefetch the program, taking resources from your workstation even though you may have no intention of ever using the program again. If you have enough unused or little-used items prefetching, over time your system will actually run slower than if you never prefetched at all. This is especially evident on systems with limited resources.

[fleamailman]

The Keith, appreciated, also there is the arguement that wanabe1 made bellow:

Quote; Ok...that being the case, what if one of the prefetch instructions becomes corrupt? The processor is going to be trying to use a bad instruction which may have quite adverse effects on the process or application being loaded. Clearing the Prefetch and rebooting repopulates the folder with fresh, good instructions for the processor to use while waiting for the memory to "catch up". unquote.


Thanks I will google to see if I can find some links to back up this conculsion, but I myself will continue to do it as standard and thank everone here too for teaching me again, if anyone knows of a good link backing the idea of delating the prefetch pls share it with me here.

Edited by fleamailman, 16 April 2006 - 10:45 AM.

[Eliot Ness]

The following link mentions that if you do clear out your prefetch files you shouldn't delete the “layout.ini” File. It goes on to say that "Once it is gone, it can stay gone on some PC'S forever, and your Prefetch Folder will never work again no matter what you do in the registry to try to rectify the problem."

http://members.rushm...~jsky/id14.html

I recently ran ATF-Cleaner to do some "Spring Cleaning" and I'm assuming that when it cleared out the prefetch files it took the "layout.ini" with it. Anyway, looking in the prefetch folder I have a "layout.ini" in there with todays date, so if it was deleted it was recreated with the other prefetch files that are in there.

Anyway, it seems to me that if XP recreates the files in the prefetch folder that it needs then a perodic cleaning of old/unused programs would be a good idea. That's my take based on what little research I've done on the subject in the last couple of days.

Edited by Eliot Ness, 16 April 2006 - 11:34 AM.

[Retired Tech]

I saw the article earlier, odd that it then goes on to show you how to replace the file