/prefetch:1 switch (WXP-Pro)

[Patrick O'Brien]

Hi All,

Adding the /prefetch:1 switch to the executable startup path of a frequently used program will decrease the applications start up time.

Example:

I use Windows Messenger quite alot. In the Target: field of the Messenger properties add /prefetch:1 to the end of the path as shown below.

"I:\Program Files\Messenger\msmsgs.exe" /prefetch:1

The result is a faster loading program as the switch automatically tells Windows to look to the Prefetch directory.

You can also speed up explorer by opening the registry and drilling down to:

[HKEY_CLASSES_ROOT\Folder\shell\explore\command]

and adding the /prefetch:1 switch to the end of the Default value path

%SystemRoot%\Explorer.exe /e,/idlist,%I,%L /prefetch:1

The same can be done for

[HKEY_CLASSES_ROOT\Folder\shell\open\command]

%SystemRoot%\Explorer.exe /idlist,%I,%L /prefetch:1

Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/

[adg]

Hi Pat. Can you please post the documentation on this? To the best of my knowledge, as long as application prefetch is "active" (setting of 1 or 3) in the registry, XP looks to the prefetch folder by default before launching a program. Thanks.

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[Patrick O'Brien]

Hello Allan,

Yes, by default Microsoft adds the /prefetch:1 switch to its Media Player properties.

"I:\Program Files\Windows Media Player\wmplayer.exe" /prefetch:1

Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/

[adg]

Sorry Pat, no offense but I still don't follow the logic behind the orinal post. Is there someplace I can see the original documentation? Thanks.

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[Patrick O'Brien]

Hello Allan,

You don't have to apologize. I don't take offense to you questioning the tweak. I think my last posting provides the documentation since it's Microsoft's own implementation.

Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/

[adg]

Hi again /images/forums/icons/smile.gif. I tried sending this question by PM but I guess it didn't get to you. Anyway, would you mind very much posting the url at the MS site where you got this from? I'd love to read the whole thing. Thanks Pat.


Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[Patrick O'Brien]

Hello Allan,

I have checked my PM capabilities and have found them to be working properly.

Just for future reference, many tweaks don't necessarily have an official write-up by Microsoft. Interestingly, we offer quite alot of them right here at WinGuides.com :).

Based on your persistent inquiry concerning a Microsoft article on this tweak, I take it that you're not satisifed with Microsoft's own default implementation within the Windows Media Player properties?

Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/

[adg]

Hmmm. I did send a PM about an hour ago Pat.

Anyway - it's just that I don't understand it. The default action for XP when any program is launched is to first check the prefetch folder (assuming, again, that application prefetch is enabled). So perhaps I'm just being dense, but I don't see why you'd need to make any changes to the command (or target) line to force it to do so when it does it anyway. And now you're talking about Media Player but the original post seemed to be about any program - so I'm really confused. I'm sure it's something obvious that I'm missing here, but now you've got me curious /images/forums/icons/smile.gif. Thanks Pat.

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[Patrick O'Brien]

Hello Allan,

I'm not sure I understand your confusion. I have found the tweak to speed up many of my programs and the access time to explorer has decreased dramatically. Just to re-clarify, Windows Media Player contains the original switch tweak in it's Target: line of it's properties. You may want to approach Microsoft directly for a detailed explanation of the /prefetch:1 switch.


Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/

[adg]

Okay. Let's take Media Player out of the picture for a moment please /images/forums/icons/smile.gif.

If you have prefetching enabled in the registry with a setting of either "1" or "3", then every time you launch a program the first place XP looks for that program is in the Prefetch folder. Adding a switch to the command / target line of that shortcut or application should not have any effect whatsoever. Either prefetching is enabled or it isn't. That's what's confusing me.

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[adg]

BTW Pat, I hope you don't think I'm trying to be difficult - not the case /images/forums/icons/smile.gif. It's just that I've always been certain my above comments about the working of Prefetch are correct. So when you said you got your info from MS I was very anxious to read it in case I've been wrong all this time (not that being wrong is all that rare an occurrance for me /images/forums/icons/laugh.gif ) but as you know I dole out this info on my site so given a choice, I prefer to be correct /images/forums/icons/laugh.gif and not provide bad info. Thanks my friend.

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[Patrick O'Brien]

Hello Allan,

Thanks for clarifying your concern. I think your clarification of the /prefetch:1 switch should be addressed to Microsoft directly. They should be able to provide to you the needed answers that you seek.

Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/

[Patrick O'Brien]

Hello Allan,

No, not at all Allan. You're not too difficult to work with.
I think you may have mis-read my original posting which stated that Microsoft has added the /prefetch:1 switch by default to the properties of Windows Media Player.

No worries, about posting the tweak on your end. You can try the tweak out for yourself and decide to post it or not.

Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/

[adg]

Thanks Pat, but I didn't mean to say I want to post this tweak - I'm afraid I still don't see the benefit. But I do appreciate your patience and responsiveness /images/forums/icons/smile.gif.

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[Patrick O'Brien]

Hello Allan,

You're welcome. It's unfortunate that you have been unable to experience the de-creased startup time for your applications and explorer as we have.

It's always a pleasure to speak with you Allan.

Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/

[adg]

Last post in this thread Pat - I promise /images/forums/icons/laugh.gif. What I've been trying to say, and apparently unsuccessfully, is that there is absolutely no reason that tweak should have any effect - positive or negative. That's why I was hoping to read some documentation on it somewhere to try to figure out the logic. But I'll stop now.

And it's always nice chatting with you too Pat. /images/forums/icons/smile.gif

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[Patrick O'Brien]

Hello Allan,

It's no problem Allan. We can continue on if you like. On the contrary Allan, I think you've explained your position. I think your next step would be to contact Microsoft to find out why they have by default, added the /prefetch:1 switch to the Windows Media Player properties.

Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/

[BertImmenschuh]

I have no explanation but an observation: I opened WordPerfect 2002 and it took 10 seconds to get to working screen. I added the /prefetch:1 to the Target: box in Properties for the same icon and it took 5 seconds to get to the same point in WordPerfect.

Good judgement comes from experience, and experience comes from bad judgement

[adg]

Hi Bert. Just as a test, could you now remove the switch and try again and let us know what happens? Thanks.

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[BertImmenschuh]

It took 8 seconds.

Good judgement comes from experience, and experience comes from bad judgement

[adg]

I just tested, also with Word Perfect. First I emptied my Prefetch folder. Then I opend WP and it took 5 seconds. Closed and reopened - 1 second. Added the switch - still 1 second. Removed the switch - 3 seconds. Tried again (without the switch) - 1 second.

The first attempt after removing the switch was two seconds slower than the attempts before and after adding the switch. I have absolutely no explanation either - just posting the results. Want to try one more time please Bert /images/forums/icons/smile.gif?

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[BertImmenschuh]

Not much change, 5 seconds with the switch and now 7 seconds without [actually just over 6 seconds].

Good judgement comes from experience, and experience comes from bad judgement

[adg]

Thanks Bert /images/forums/icons/smile.gif

Allan
<a target="_blank" href=http://www.tweakdatabase.com/idealbb>tweakxp.com</a>

[Mosaic1]

What happens after a reboot. How much of the program remains in memory if you are testing this. It would be better, I think to run it against itself with exactly the same background tasks running etc.

Hi Pat,
I have tried several times in the past months to PM you. I always got a message that this Member is not accepting PM's. I gave up a while back.

Mo

[Patrick O'Brien]

Hi Mo,

I'm not sure. I have the setting turned on to accept PM's for this account. If you tried on the pobrien account then the message is correct, I have turned them off for that account as I don't use it anymore. I'll ask Simon if he can help me.

It's good to read you again :)

Patrick



Regards,

Patrick O'Brien
---
WinGuides.com - Windows Guide Network
http://www.winguides.com/