info about prefetcher and partial defrag

[da_test]

Hello, I saw this on the net:

To find this tool browse to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SessionManager\Memory
Management\PrefetchParameters

The important key is EnablePrefetcher. Default value for this SHOULD
be3.
1 means to prefetch boot processes only.
2 means prefetch applications only
3 means prefetch both (make sure you're using this)

My understanding is that if the setting is 2, application wont
be prefetched during application start.

However (correct me if I'm wrong) the partial defragment thats
done every 3 days or so, will still defrag ALL the layout.ini,
files related to system start AND files related to application
startup.

Is this true or false?
Dave

 

[Guest]

The important key is EnablePrefetcher. Default value for this SHOULD
be3.
1 means to prefetch boot processes only.
2 means prefetch applications only
3 means prefetch both (make sure you're using this)

My understanding is that if the setting is 2, application wont
be prefetched during application start.

I'm not so sure that I agree with this advice, or at least I would qualify
it as follows. When you boot your machine, all code loads from the hard
drive into RAM, and a setting of 1 will make this process go faster than 2 or
3 (how much faster is a separate question -- we are probably talking seconds
at most, but probably enough to notice).

If you use a setting of 2 or 3, your application will run faster when you
are loading it from your hard drive to RAM. However, if you already have
lots of RAM, it will stay in the system cache, meaning that the next time you
start the program it will load from the system cache (much, much faster!)
than the hard drive -- in which case you don't get the benefit of the 2 or 3
setting. I don't know how much RAM we are talking about here, so I'll throw
out an arbitrary number -- say, 512 MB. If you have 512 MB or more, you are
probably better off with a setting at 1. Otherwise, try 2 or 3.

You may also benefit from a 2 or 3 setting if you reboot your computer every
day instead of always leaving it on or merely logging in and out. The reason
is because when you leave your system on or log in and out, Windows XP
doesn't flush the system cache. When you reboot, it does.

However (correct me if I'm wrong) the partial defragment thats
done every 3 days or so, will still defrag ALL the layout.ini,
files related to system start AND files related to application
startup.

Is this true or false?

That's my understanding. If you use PerfectDisk as your defragger, it also
puts this file at the very begnning of the drive.

Ken

 

[da_test]

That's my understanding. If you use PerfectDisk as your defragger, it also
puts this file at the very begnning of the drive.

Ken

Thanks for the info - at least with perfectdisk you exclude
files and folders if necessary.

The problem I have with XP's partial defrag is that it wants
to defrag everything associated with the apps,
even media files,
For example, the WAV or AVI files themselves.

Another example is a usenet newsreader and it's
database, whch can become quite sizeable.
Files like that are volatile, in constant flux,
amd trying to "optimize" every 3 days is meaningless.
Dave

 

[Guest]

The problem I have with XP's partial defrag is that it wants
to defrag everything associated with the apps,
even media files, For example, the WAV or AVI files themselves.

Are you sure about this? I thought that the partial defrag only defrags
application files and their associated .dll files.

Another example is a usenet newsreader and it's
database, whch can become quite sizeable.
Files like that are volatile, in constant flux,
amd trying to "optimize" every 3 days is meaningless.

Same comment. I would seriously doubt that the three day defrag touches
data files of any type.

Ken

 

[da_test]

Are you sure about this? I thought that the partial defrag only defrags
application files and their associated .dll files. I wished it did just this


Same comment. I would seriously doubt that the three day defrag touches
data files of any type.

Ken

I can confirm that it does. They are certainly referenced
in layout.ini, bit to make sure,
I forced the partial defrag by issuing the command:
rundll32 advapi32 ProcessIdleTasks

When it was done I used the perfectdisk trial to "find"
the files in question, sure enough, they were in the
contiguous area created from the process above.

Dave