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

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• 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

 

[EdF]

Hi

I have a new HP2110ca tablet PC.

I have been working my way thru the tutorials to essentially speed up operation and boot time.

When I first looked at this tutorial I had the option of 2 processors ( as I have a dual core chip). At that time I did not change the number, which was set to 1.

Yesterday I returned to the option and now only one processor is shown in the "# of processors" box.

At no time have I made the boot option changes permanent.

Any idea what has happened? Can I restore the option thru a registry fix?

Ed

I finally solved this problem. I had ignored it for a while but decided to tackle it again yesterday. I ran Msinfo32.exe and it reported I had only 1 core and 1 logical processor. Also I downloaded a gadget (All CPU Meter) and it only showed 1 core in use.

Not knowing quite what to do next I opened the Boot screen-Advanced Options and de-selected the # of processors box(see JPG). I then did a reboot and went back to the Boot screen-Advanced Options and, lo and behold, I now had a choice of 1 or 2 processors again.

I rechecked withMsinfo32 and it reported I now have 2 cores and 2 logical processors. Also, All CPU Meter shows both cores in use.

Such a simple solution, and I now have a more responsive system.

Ed

 

[Brink]

Thank you for posting your results Ed. I'm happy to hear that you got it sorted out.

Shawn

 

[Lightning Speed]

Great guide thanks Brink

 

[ScousaJAY]

Re: what is the Detect HAL for???

what is Detect HAL?? just curious!

 

[Brink]

Hi Scousa4lyf, and welcome to Vista Forums.

HAL stands for Hardware Abstraction Layer. This setting forces Vista to check and verify with HAL about your CPU at every boot. This link will help explain more about HAL in detail.

Hardware abstraction layer - Wikipedia, the free encyclopedia

A thin layer of software provided by the Hardware Manufacturer that hides, or abstracts, Hardware differences from higher layers of the Operating System [Windows]. By means of the filter provided by the HAL, different types of Hardware look alike to the rest of the Operating System. This allows the Operating System to be portable from one Hardware Platform to another. The HAL also provides routines that allow a single Device Driver to support the same Device on all Platforms.

Hope this helps,
Shawn

 

[genesis1]

Didn't notice much difference on my system after changing the settings to 4 processors.What is the average time for start up on Vista from a hard boot? Im running Vista home premium 32 bit, quad core 3gb ram.

 

[Brink]

Hi Genesis1,

You may test it every so often with and without this set to see if their is any difference worth keeeping it set or not.

It varies to much from person to person depending on what you have running at startup and your hardware for a true average startup time, but you could expect anything from 1 to 5 minutes I suppose.

Hope this helps,
Shawn

 

[hungry_raptor]

Hi Shawn,

Thanks for the reconfig. My fastest boot time, prior to your fix, was 82 seconds. After the change my boot time was 52 seconds.

FYI: Dell Insperion 530
Intel Duo Quad Q9300 2.5 Ghz x 4
6 GB

Thanks,

 

[Brink]

Your welcome Larry, and welcome to Vista Forums.

Shawn

 

[crazydude007]

Before: 136 seconds

After: 75 seconds

Thanks soooo much! :D

 

[Brink]

You're welcome CrazyDude007.

Shawn

 

[dinesh]

i have intel core 2 duo processor, which number should i choose as the number of processors?

 

[mansrm81]

If you have a dual core processor you can choose 2.

 

[Brink]

i have intel core 2 duo processor, which number should i choose as the number of processors?

Hello Dinesh,

It depends on the CPU model number for the size of your L2 cache, but Intel Core 2 Duo CPUs use a shared L2 cache. So you would use the number for the total size of your L2 cache for your CPU.

Intel® Core™2 Duo Processor Overview

With Intel Core 2 Duo processors powering your desktop and laptop PCs you'll get the latest arsenal of performance-rich technologies, including up to 6MB of shared L2 cache, up to 1333 MHz Front Side Bus for desktop, and up to 1066 MHz Front Side Bus for laptop, you've got the future of computing now, and only from Intel:

Hope this helps,
Shawn

 

[dinesh]

Hi Shawn,
my processor has a L2 cache of 2 MB. so shall i select 2 as number of processors?

 

[Brink]

Hello Dinesh,

This setting has nothing to do with the L2 cache, but instead with how many cores your processor has. You would select the highest number available instead. You should have 2 as the highest number listed for you CPU.

Hope this helps,
Shawn

 

[dinesh]

you are the man . . . Shawn.

 

[Brink]

Dinesh,

Did you see any improvement in boot up time?

 

[dinesh]

Not much but yes earlier my system took almost 120 seconds to reach the desktop but now it boots up in 80-90 secs. so there's some improvements.

 

[Korki Buchek]

Hi Brink and All,
I have a Phenom Quad-Core 9600 CPU in a G8way GT5676.

Got an inital boot time of 139 seconds. When I go to change the number of processers to boot in SysConfig, it shows 1

However,
It Will Not let me enter any other values. The dropdown box shows Only the number 1.
I Think this is a G8way/AMD conspiracy. Any work arounds?

Thanks, John