Page 1 of 1 1
Topic Options
#157795 - 2006-02-23 11:46 PM Purging XP prefetch
Shawn Administrator Offline
Administrator
*****

Registered: 1999-08-13
Posts: 8611
Does anyone have any direct experience with purging the Windows XP prefetch folder, in terms of it being a good thing or bad thing to do (improving performance somehow)... some sites recommend doing it, and some sites don't. My gut feeling is that it prolly aint a good thing to be doing - or at least counter-productive.

-Shawn

Top
#157796 - 2006-02-24 01:10 AM Re: Purging XP prefetch
NTDOC Administrator Offline
Administrator
*****

Registered: 2000-07-28
Posts: 11634
Loc: Space
I've done it many time Shawn. It's sort of like the %TEMP% folder in the sense that it should remove OLD entries and only keep new ones. So, I would not recommend deleting the files all the time, but maybe once every month or so and I find that it does improve performance.

The system attempts to manage this for best performance on it's own but sometimes I think it either just gets clogged or lost and doesn't remove ancient entries.

It will take a few reboots and running of applications to reset the performance algorithms to best performance again.

Top
#157797 - 2006-02-24 01:16 AM Re: Purging XP prefetch
Shawn Administrator Offline
Administrator
*****

Registered: 1999-08-13
Posts: 8611
So what are you saying - that the prefetch can get "stale" and that this can hinder performance ... how does purging the prefetch improve performance ? btw - I know very little about the prefetch, so just asking questions here bud. This idea is being floated around our company as something we might want to do - just want to understand the "why" and "how come".
Top
#157798 - 2006-02-24 01:21 AM Re: Purging XP prefetch
NTDOC Administrator Offline
Administrator
*****

Registered: 2000-07-28
Posts: 11634
Loc: Space
Yes (imho) "stale" may be a good word for it.

As for doing it on user desktops, hmmm never though much about it. The performance gain is not drastic one way or another but sometimes is at least noticed by someone that is in tune with how their system operates.

Prefetch is a utility that loads commonly used applications to RAM when the system starts.


Windows XP: Kernel Improvements Create a More Robust, Powerful, and Scalable OS
http://msdn.microsoft.com/msdnmag/issues/01/12/XPKernel/default.aspx
 

Top
#157799 - 2006-02-24 01:28 AM Re: Purging XP prefetch
Shawn Administrator Offline
Administrator
*****

Registered: 1999-08-13
Posts: 8611
idk - based on my read, and reading this:

Quote:


Here is an excerpt from Ryan Myers, a developer on Microsoft's Windows Client Performance Team:

XP systems have a Prefetch directory underneath the windows root directory, full of .pf files -- these are lists of pages to load. The file names are generated from hashing the EXE to load -- whenever you load the EXE, we hash, see if there's a matching (exename)-(hash).pf file in the prefetch directory, and if so we load those pages. (If it doesn't exist, we track what pages it loads, create that file, and pick a handful of them to save to it.) So, first off, it is a bad idea to periodically clean out that folder as some tech sites suggest. For one thing, XP will just re-create that data anyways; secondly, it trims the files anyways if there's ever more than 128 of them so that it doesn't needlessly consume space. So not only is deleting the directory totally unnecessary, but you're also putting a temporary dent in your PC's performance.





that is an excerpt from here:

http://blogs.msdn.com/ryanmy/archive/2005/05/25/421882.aspx

I still dont understand why purging the prefetch would improve performance - in fact, based on the information you provided - the prefetch gets "trained" and "optimized" as time goes on (through smart defragging etc) ... I figure that purging the prefetch you would actually "loose" this streamlining that has occured over many reboots.

-Shawn

Top
#157800 - 2006-02-24 01:39 AM Re: Purging XP prefetch
NTDOC Administrator Offline
Administrator
*****

Registered: 2000-07-28
Posts: 11634
Loc: Space
Keyword there Shawn SHOULD

From my own experience I can only say that it does not always work as explained. Removing them too often would decrease performance, which is what I said above.

Different users and different systems will produce different results as well all work different. For me about a month to two months cleaning it out will give me a very slight improvement on performance within a few days.
 

Top
#157801 - 2006-02-24 01:56 AM Re: Purging XP prefetch
NTDOC Administrator Offline
Administrator
*****

Registered: 2000-07-28
Posts: 11634
Loc: Space
For normal users I wouldn't clean it out any more often that every 6 months or so.
Top
Page 1 of 1 1


Moderator:  Arend_, Allen, Jochen, Radimus, Glenn Barnas, ShaneEP, Ruud van Velsen, Mart 
Hop to:
Shout Box

Who's Online
0 registered and 2220 anonymous users online.
Newest Members
Viginette, ManuvdWielNL, Sir_Barrington, batdk82, StuTheCoder
17888 Registered Users

Generated in 0.062 seconds in which 0.03 seconds were spent on a total of 12 queries. Zlib compression enabled.

Search the board with:
superb Board Search
or try with google:
Google
Web kixtart.org