1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Why does device manager show 2 CPU's?

Discussion in 'PC hardware help' started by kiwi1, Feb 3, 2007.

  1. kiwi1

    kiwi1 Regular member

    Joined:
    Jun 9, 2006
    Messages:
    374
    Likes Received:
    0
    Trophy Points:
    26
    Hi. I've just noticed Both windows and linux list two CPU's in my comp, linux even gives a different bogomips number for CPU #2. screenshots- http://imagegrotto.com/collection-1167
    The problems is, I dont have two CPU's or a dual core.
    I have a P4 2.93ghz
    Just wondering why there's two of em?
     
    Last edited: Feb 3, 2007
  2. gtjr_ph

    gtjr_ph Regular member

    Joined:
    Oct 18, 2006
    Messages:
    148
    Likes Received:
    0
    Trophy Points:
    26
    maybe hyperthreading is enabled
     
  3. BigDK

    BigDK Regular member

    Joined:
    Dec 1, 2005
    Messages:
    1,637
    Likes Received:
    0
    Trophy Points:
    46
    You have dual core P4
     
  4. hangfire1

    hangfire1 Member

    Joined:
    Nov 18, 2004
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    11
    You have Hyper Threading enabled. With this enabled your OS sees two logical processors instead of one physical processor. On Windows, if you use Task Manager, you will see the CPU usage of each processor report different usage levels. Same should be true in linux but knowing very little about linux I have no idea how you would go about observing this.

    If you want to disable HT you'll need to do this from the BIOS.
     
  5. Wilbow

    Wilbow Guest

    Would you want to disable Hyperthreading for any reason?
     
  6. hangfire1

    hangfire1 Member

    Joined:
    Nov 18, 2004
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    11
    Perhaps. I am not 100% sure but it is possible that some apps don't like HT. I know that when I flash my DBOX2 I get a warning that HT may prevent things from working - it has always worked for me however.

    HT enabled draws more power from your power supply so I suppose if you have a naff under rated power supply it might be an idea not have it enabled. The safety features of the power supply 'should' protect the processor if anything goes wrong (I use the word 'should' because it might not) As it draws more power from the power supply obviously the power supply draws more power from the mains so it will cost more to run you PC, I doubt you'll notice it much on your utility bill though!

    Best leaving it on, everything runs faster and if you want to experiment (be careful though) you could try playing with processor affinity. This is where you tell a process to use either of the virtual CPU's or both.
     

Share This Page