13" rMBP has quad core i7

Discussion in 'MacBook Pro' started by mac8867, Dec 1, 2012.

  1. mac8867 macrumors 6502

    Joined:
    Apr 5, 2010
    Location:
    Saint Augustine, FL
    #1
    Hi everyone... I am usually just a "lurker" around here. I just got my new rMBP 13", ordered an i7 model. The first thing I noticed was iStat Menus showed 4 processors... so I checked from the command line with "sysctl -n hw.ncpu"... and it also reports four processors.

    So, perhaps this had been discussed... but I thought it was odd. My best guess is that it's not really a quad core, but everything points that way. Anybody have and insight?
     
  2. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #2
    It is a dual core i7 with two threads per core, thus it has two physical cores with two virtual cores per physical core, which appear as four cores in iStat or Activity Monitor.
    It is called "HyperThreading" (HT).
     
  3. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #3
    That's because the i7 uses hyper threading and basically shows virtual cores
     
  4. mac8867 thread starter macrumors 6502

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    Apr 5, 2010
    Location:
    Saint Augustine, FL
  5. NathanA macrumors 6502a

    Joined:
    Feb 9, 2008
    #5
    Right: it's a hyperthreaded processor. Thus each core actually appears as 2 CPUs to the OS, even though there aren't really 2. Your dual-core i7 thus looks like a 4-CPU SMP system from a software perspective.

    Similarly, OS X thinks that my quad-core 15" rMBP, which also has a hyperthreaded proc, has 8 CPUs in it, even though there are "only" 4. :)

    -- Nathan
     

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