Does changing the number of processors under Boot Advanced Options affect computer speed?


I have Dell XPS 15z Windows 7 Home Premium (64 bit) OS with 4GB RAM, intel i5 processor @2.5 Ghz and 1GB nVidia Graphics.By default, it uses 4 cpu however my system is slow in booting up and seems lazy doing simple things like opening programs and files, i mean the response is slow.

However, when I reduced the number of process to 2 or 3 or 1, the boot up time reduced significantly and system responded quick to any actions but there was lag as it was clear with gaming.

I don't know what to do.....it's so embarassing to have high performance gaming computer but still sucks at doing normal operations especially booting up - it takes more than 4 minutes!

I have very few programs to run at start up.

Any suggestions to improve the speed of my system?

  • Is it a clean install or riddled with OEM apps? Can you check Task Manager to watch which app take over a core (25% on CPU usage)?
    – Martheen
    Feb 21, 2013 at 8:33
  • Is there a difference between the time it takes with multiple or one CPU till the first "lifesign" of Windows (Bootscreen) shows up? If there is a difference, then it is probably a hardware issue (or BIOS issue). Feb 21, 2013 at 9:16
  • Ok... I was to slow with my comment. You updated you question in the meantime. I there a difference if you start Windows in the safe-mode (I have just a german windows and I am not sure about the translation) and the normal startup? I mean: I a difference between the multiple cpu and one in the safe mode? Feb 21, 2013 at 9:36
  • @MartheenCahyaPaulo There are pre installed Dell apps like dell datasafe, dell camera, but i have configured not to run those apps during start up.Also when 4 processors are used, the cpu reading just aroud 10%
    – Nigel
    Feb 21, 2013 at 13:05
  • @ChaosCakeCoder No, but time difference is only between the login screen and when the desktop shows up.I tried booting in safe mode, it's pretty fast.
    – Nigel
    Feb 21, 2013 at 13:07

1 Answer 1


The processor is one component of a PC that affects speed, but there are many factors that contribute to a slow computer.

If you notice speed problems on boot, and opening folders, programs and other files, more than likely it's not your processor that is the culprit, but your hard drive and RAM. Buy an SSD and make sure you have at least 4 GB (preferably 8 if you're gaming) of the fastest memory your board can support. Perform a clean install of your O/S* from a non-OEM disc (crapware is crapware). *Install the **latest drivers for your devices*.

Disable services that you don't need, as well as any startup programs that can be manually launched when needed.

To answer your original question, yes, crippling a processor by only using one of its cores will slow down your computer. Would only using one cylinder in your engine make it go slower?

  • 3
    And just a side note, taking the time to uninstall this and that might speed up your PC by 0.00001%, but in the end the havoc that has been wrought on your registry can't be undone without a clean O/S install. I'm one of those people that says "When in doubt, start fresh. Work smarter, not harder."
    – user201262
    Feb 21, 2013 at 19:44
  • 2
    Excellent answer. And solid advice imo. Feb 21, 2013 at 19:45

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