Processes run on 1 cpu (in HT system) only

Discussion in 'General Hardware' started by hansrijf, Jan 12, 2007.

  1. hansrijf

    hansrijf sh! it stinks Folding Team

    Messages:
    277
    Location:
    Amsterdam, The Netherlands
    Hello,

    I have this strange problem, without any changes made to system, os or bios (as far as I know anyway): all of a sudden the processes in the taskmanager run on 1 CPU only. I have hyperthreading turned on in the BIOS but they all run on CPU 2 only.

    Is there a registrysetting to enable/disable a cpu on a HT system? In devicemanager there are no problems, "both" cpu's show up in the devicelist.

    Who can help?

    Thanks
    Hans
     
    Last edited: Apr 21, 2007
  2. hansrijf

    hansrijf sh! it stinks Folding Team

    Messages:
    277
    Location:
    Amsterdam, The Netherlands
    bit disappointed...
     
  3. LordOfLA

    LordOfLA Godlike!

    Messages:
    7,027
    Location:
    Maidenhead, Berkshire, UK
    If you could run applications on a second cpu with HT I'd be wondering where my second chip came from. HT = 1CPU that runs 2 threads at a time.

    If windows doesn't schedule tasks to the "Virtual" cpu it obviously doesn't need to.
     
  4. ShepsCrook

    ShepsCrook Red Sox Fan!

    Messages:
    1,489
    Location:
    Knightdale
    Yeah, just because Windows shows there are two processors, it doesn't mean you have 2 processors. This is true with the Pentium 4 HT processors. The processor like mentioned before shows a "Virtual" CPU along with a "Physical" CPU. There is only 1 CPU on your machine, 1 Core. But runs 2 threads much like a dual core would. Does this perform equal to a dual core? The answer is NO.
     
  5. Brad

    Brad Moderator Political User Folding Team

    Messages:
    2,280
    Location:
    Cary, NC
    wow, what a top that was.
     
  6. LordOfLA

    LordOfLA Godlike!

    Messages:
    7,027
    Location:
    Maidenhead, Berkshire, UK
    Dual core will happily run more than 2 threads faster than HT :) as will single core CPU's that are not netburst based :)
     
  7. ray_gillespie

    ray_gillespie Moderator Staff Member Political User

    Messages:
    1,692
    Location:
    Birmingham, UK
    I thought he meant that his HT CPU is only showing up a single graph on his CPU usage history. A HT CPU should show up as two graphs as Windows treats it as two.
     
  8. hansrijf

    hansrijf sh! it stinks Folding Team

    Messages:
    277
    Location:
    Amsterdam, The Netherlands
    This is correct. Even though my BIOS is setup as "hyperthreading enabled" under taskmanager the programs only run under "CPU 1" and nothing runs under "the other CPU" although "both CPU's" are visible as a graph.

    Specially for MS Flightsimulator I want to have FS9 run under "CPU 1" and the rest of the few necessary programs under "CPU2"

    Thanks so far
     
  9. ShepsCrook

    ShepsCrook Red Sox Fan!

    Messages:
    1,489
    Location:
    Knightdale
    ohhhh.... I'm sure you've tried Disabling HT in the bios, then starting windows, then restarting, then enabling HT. Otherwise, try updating your bios.
     
  10. LordOfLA

    LordOfLA Godlike!

    Messages:
    7,027
    Location:
    Maidenhead, Berkshire, UK
    you cant dictate what cpu stuff runs on. Thats down to the windows thread scheduler. I twill balance loads if it deems it necessary, but it knows thats not too helpful with HT anyway.
     
  11. hansrijf

    hansrijf sh! it stinks Folding Team

    Messages:
    277
    Location:
    Amsterdam, The Netherlands
    Yes tried this too. Didn't work....

    It is not such a big problem, everything runs well anyway. Would just like to know why it happens.