MULTIPORCESSORS AND HYPERTHREADING

  • Thread starter Thread starter clone_enolc
  • Start date Start date
C

clone_enolc

IN WIN XP, IT CAN ONLY HANDLE TWO symmetric
multiprocessors. Is that still true and if so, if
hyperthreading is on, does one physical processor now
count for the max two symmetric multiprocessors in xp?

Clone_enolC
 
XP Home can use hyperthreading, which will appear as two processors, but
won't support two separate processors. Pro will support two separate
processors, with or without hyperthreading.
 
So...
In Pro, with two Xeons with hyperthreading on, this will
show as four processors?

Thanks Steve,
clone_enolc
 
and... if it doesn't show as four processors, since XP pro
can only handle two symmetric multiprocessors, would it
not be ideal to disable hyperthreading?

Thanks
clone_enolc
 
clone_enolc said:
and... if it doesn't show as four processors, since XP pro
can only handle two symmetric multiprocessors, would it
not be ideal to disable hyperthreading?
Click to expand...

XP's CPU counting logic counts physical CPUs when deciding how many
processors are installed, but allows for hyperthreading when configuring the
SMP capabilities. Hence, XP Home supports a single physical CPU but allows
for two logical CPUs when a hyperhtreaded CPU is used. Similarly XP Pro
allows for two physical CPUs which are seen as four logical CPUs when
hyperthreaded CPUs are in use. No, disabling hyperthreading is not a good
idea unless you have software that seems to run unreliably with multiple
CPUs.
 
Back
Top