Boot Advanced Options - Number of Processors

How to Change the Number of Processors Used at Boot Up in Vista​

   Information

If you have a multiple core CPU (Ex: Intel Core Duo or Quad CPU) or multiple CPUs, then this will show you how to change the Number of Processors that will be used during boot up for troubleshooting and debugging purposes to be able to determine if there is a problem with a single processor/core, or for a programmer to test their code against a single core while running on their multi-core system.

   Note

Vista will use all your processors by default at boot up without this Number of Processors setting box checked. Using all of your available processors (cores or CPUs) durring boot allows the computer to boot faster only because a multiple core CPU or multiple CPUs can handle and do more at once than a single core or CPU. Multiple cores do not actually increase the speed, but only increase the number of processor cores working on the job which in turn has the job finish quicker. If you do not have much running at startup, then you may not notice much improvement in how long it takes to startup.

   Tip

People have reported that by checking this setting and selecting all of their available CPUs, they have seen a performance increase in boot up speed despite the Note above . See the example below. If it does not help, then you can do step 7 to undo this and go back to the default settings.

   Warning

Selecting a lower amount of processors to use at boot up than you actually have can increase the amount boot up time causing a longer boot.

EXAMPLE: Boot Up Time Before and After
NOTE: This is the before and after boot up time for my computer after I changed it to use all 4 cores. For fun you can post your results here: ReBoot Time

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Here's How:
NOTE: Before you do this, you should see what your current boot up time is so you can compare it to what it will be before and after applying this.

1. Open the Start Menu.​

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2. In the white line (Start Search) area, type msconfig and press Enter.​

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3. Click Continue in the UAC prompt.​

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4. Click on the Boot tab. (See screenshot below)​

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5. Click on the Advanced options button.​

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6. To Change the Number of Processors at Boot -​

A) Check the Number of processors box, then click on the drop down arrow and select the number of available processors (cores or CPUs) you want to have used at boot up. (See screenshots below step 7)​

NOTE: To test to see if this can speed up your boot time or not, then select the highest number listed for all of the available processors to be used at boot up and check the Detect Hal box.​

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B) Click on OK.​

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C) Go to step 8.​

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7. To Restore the Default Number of Processors at Boot -​

A) Uncheck the Number of processors box.​

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B) Click on OK.​

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8. Check the Make all boot settings permanent box and click on OK. (See screenshot below)​

NOTE: If you do not check this, then you will Selective startup dotted instead of Normal startup under the General tab. You can still make changes again by checking this again after any changes.​

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9. Click on Yes at the confirmation window. (See screenshot below)​

NOTE: You can restore or make changes to this again later if you want. I will confirm it. Just remember or write down what you had set (checked or unchecked) before if you wanted to restore back to those settings later.​

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10. Check the Don't show this message again box. (See screenshot below step 11)​

NOTE: You will not see this again after checked.​

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11. Click on the Restart button.​

NOTE: If you checked the box and want to restore this Restart box, see: How to Restore the System Configuration Restart Prompt in Vista​

WARNING: This will restart the computer immediately. Make sure you save and close anything open you do not want to lose.​

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12. After you have started back to the desktop, you can check to see what your new boot up time is for fun.​

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That's it,
Shawn

Related Tutorials

---

• How to Speed Up Shutdown in Vista
• How to Speed Up Vista Boot Up Time
• How to Speed Up the Performance of Vista
• How to Set Vista for the CPU L2 Cache Memory Size
• How to Set the Processor Affinity for a Application in Vista
• How to Make a Program or Process Run with a Higher or Lower CPU Priority in Vista
• How to See What Your Boot Up Time is in Vista
• How to Logon Automatically at Startup in Vista
• How to Check and Change the Startup Programs in Vista

 

[Brink]

Hello John.

LOL, could be. See if resetting the BIOS back to factory defaults can help ID the CPU correctly. If you have not already, then you might also flash the BIOS with the latest version.

Shawn

 

[micman888]

Hi y'all
just wondering , is this process reversible?cuz in step 9 its says this

so how do you do this just incase it takes longer to boot

ps excellent forum by the way

 

[mansrm81]

Yes its reversible just remember what you had before you changed it.

 

[micman888]

but it says it'll be permanent and you can't undo these changes
so you can just go back and make the changes or do you have to do sys restore?

 

[Brink]

Hello Micman,

That message is misleading. Yes, you can go back and make changed to it again. See note under step 9. You will just need to repeat steps 8 and 9 in this tutorial again after making the changes to actually be able to change them.

Hope this helps,
Shawn

 

[micman888]

excellent . thanks for the quick replies
i'm away to give it a bash

 

[micman888]

WOW............reboots amazingly fast now

 

[Brink]

That's great news Micman. Thank you for posting back your results.

Shawn

 

[accelrate]

Hi guys. I have the weirdest thing happen when I try this. I set it to use all of my Quad Core, and it forgets to load up some of the process on start up usually found in my system tray, namely my compro stuff. Its the oddest thing. Without these icons my remote and the DTV thing doesnt work. LOL. Anyone else encounter this. When I change it back it fixes it.

 

[Brink]

Hello Accelratre,

That is strange. It should have no affect on startup programs.

 

[Korki Buchek]

Hi guys. I have the weirdest thing happen when I try this. I set it to use all of my Quad Core, and it forgets to load up some of the process on start up usually found in my system tray, namely my compro stuff. Its the oddest thing. Without these icons my remote and the DTV thing doesnt work. LOL. Anyone else encounter this. When I change it back it fixes it.

I have a Quad-Core as well, but when I go to set the correct number of cores (4) it Only options for the number 1. I have a Gateway GT5676 running Vista sP1 x64. I take it you have a different system.

 

[rawbery79]

Well, I tried this trick...had a startup time of 156 seconds, changed from 1 to 2, restarted...and 156 seconds. I even reduced the number of programs that start at startup! And this thing randomly freezes up too....ARGH. I am so frustrated.

 

[Brink]

Hello Rawbery,

Not everyone will see a gain in performance from this. Since you did not, I would recommend setting it back to the default setting of being unchecked.

Sorry you did not gain anything from it.

Shawn

 

[rawbery79]

It's okay--I think I've figured out my other problems that caused the slowdown. and I've put a few cool little tweaks from here on my laptop. I am really amazed at the tutorials here, and when I get a little extra money, I am definitely going to try to donate--if all goes well, you saved me from taking this in for service during the last three weeks of the semester! If I can get to the end with no problems, I'll totally help the site out, lol.:D

 

[Brink]

Rawberry, I'm happy to hear that you got the other issues sorted.

Shawn

 

[Airbot]

Yeah, this didn't improve my reboot at all. It actually increased it.
My first reboot.


Reboot after checking 2 processors.


My boot up time decreased by one second after unchecking "Time to display list of operating systems".

 

[silverhawk184]

this works wonders.
from when i hit enter at my Grub menu to when the speech recognition toolbar makes noise; it was 46 sec, now its 24 sec ... but then again, the first time was after making windows service pruning and it probably had to reconfigure.
thanks


Gateway M285-e
T7400 2.168Ghz
2GB
+dreams enabled

 

[Brink]

You're welcome Silverhawk, and welcome to Vista Forums.

Shawn

 

[silverhawk184]

thanks, i have hardly use standby anymore, it's so fast ... and drains less battery

i heard that the engineers of windows 7 have a goal of <15s ... wow

also, read this:
"As the system arrived to us, the off-the-shelf configuration had a ~45 second boot time. Performing a clean install of Vista SP1 on the same system produced a consistent ~23 second boot time. Of course, being a clean install, there were many fewer processes, services and a slightly different set of drivers (mostly the versions were different). However, we were able to take the off-the-shelf configuration and optimize it to produce a consistent boot time of ~21 seconds, ~2 seconds faster than the clean install because some driver/BIOS changes could be made in the optimized configuration." - http://blogs.msdn.com/.../boot-performance.aspx

 

[Brink]

You're welcome Silverhawk. It would be nice to have a 15s startup. Perhaps it may be with a SSD drive??