Gordon Dexter on 10 Aug 2009 05:43:01 -0700


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Re: [PLUG] Identifying CPU features/model/etc. (WAS: Is the Atom an x86?)


brent timothy saner wrote:
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brent timothy saner wrote:
  
Art Alexion wrote:

    
Anyway, htop reports the atom as dual core and actually shows different
processor use for each of the cores.  I don't think that is accurate.
      
cat /proc/cpuinfo

if you see two processors, it's dual core.

additionally, if it's a Silverthorne (Z series), it's definitely
single-core. if it's a Diamondville (N, 200, 300 series) it's definitely
 dual-core. this information can be determined via /proc/cpuinfo and was
collected from the wikipedia article mentioned in the previous thread.
    


whoops, small correction. only SOME of the N-series, it seems, are
dual-core.
  
I have an N270, and it is definitely single core according to a well-cited Wikipedia article, but it shows up as two CPUs because it supports hyperthreading.

I have an circa 2003 dual Xeon box that has four penguins at the top of the screen when booting, in spite of having only two physical CPUs, because those CPUs (which were made long before the advent of dual-core systems) still have hyperthreading.

To respond to the original question, I'm currently running Ubuntu on an Eee 901 with the N270.  The Atom is perfectly capable of exeuting x86 code.  What Intel did to keep the power drain down, instead of changing architectures, is use in-order execution to make the CPU much simpler.  All other Intel CPUs have used out of order execution, for the past several generations, but it has substantial power costs relative to the performance gains, so Intel didn't use it in the Atom.

See http://en.wikipedia.org/wiki/Out_of_order_execution for more detailed information.

--Gordon

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