Is 15" i7 actually slower than base iMac?

Discussion in 'MacBook Pro' started by skiltrip, Jan 2, 2011.

  1. skiltrip macrumors 68030

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    #1
    According to geekbench scores, the base model 2010 iMac scores higher than the 2.67ghz i7 model of 15" MacBook Pro. This seems at odds with what one would think. I know the iMac has a greater ghz rating, but I thought the superiority of the i7 chip would more than make up for that. Is the iMac faster, or Is there more to these geekbench scores than meets the eye?
     
  2. standingquiet macrumors 6502

    standingquiet

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    #2
    I was thinking of this recently and thought would a 2.8ghz core 2 be faster than than a 2.4ghz i5
     
  3. Hellhammer Moderator

    Hellhammer

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    #3
    i7 doesn't make the CPU any special. Both chips are based on the same Nehalem microarchitecture, thus the clock speed and amount of cache are the only things separating them. It is true that the base iMac is faster due to its clock speed.
     
  4. skiltrip thread starter macrumors 68030

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    #4
    Thanks for the response. It's hard to keep it in perspective when general statements get thrown around all the time like "the i3 is a budget CPU" and "the i7's are screamers!". Lol.
     
  5. Hellhammer Moderator

    Hellhammer

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    #5
    Well, you are looking at two different class of CPUs. MBPs use mobile CPUs with TDP of 35W. The i7-620M and 640M are the best CPUs with TDP of 35W, that's why they are called i7. iMacs use desktop CPUs and the i3s have TDP of 73W. They are considered to be low-end for desktops as they are one of the cheapest and slowest CPUs available atm. There are plenty of much faster CPUs (mostly quad core) that are called i5 and i7.
     
  6. scrapperx, Jan 12, 2011
    Last edited: Jan 12, 2011

    scrapperx macrumors newbie

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    Jan 12, 2011
    #6
    My MBP Geekbench Score

    This may help.

    MBP 15" 2010
    i7-640M 2.8 GHz
    500GB HD
    8GB RAM
    5400rpm

    Geekbench score of 6643
     

    Attached Files:

  7. WardC macrumors 68030

    WardC

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    #7
    The Sandy Bridge Mobile Quad-Core i7 2630QM will be able to crush any of the current iMac desktop i3 offerings. Just wait a few months.
     
  8. mwhq macrumors member

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    #8
    Yawn :D
     
  9. NickZac macrumors 68000

    NickZac

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    #9
    If you want it for reference, my C2D 13 is about 4,800

    I'll go test our C2D iMac for comparisons as well
     
  10. NickZac macrumors 68000

    NickZac

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    #10
    Hmm

    The C2D 2.8GHz iMac (23.5 inch) ran about 3,600. It does however only have 2GB of RAM and it is DDR2 at a slower speed and the hard disk drive is near full. Also, the people who use it often have no idea what the hell they are doing so who knows.
     
  11. WardC, Jan 12, 2011
    Last edited: Jan 12, 2011

    WardC macrumors 68030

    WardC

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    #11
    By comparison, my 3.33GHz 6-core Mac Pro is 16,107 :eek:

    Look at the 12-core models and you are talking Geekbench scores of 25,000+

    I will have to see what my single-threaded scores look like.

    EDIT: The 3.33GHz 6-core Mac Pro is only 7-8% faster than the 2.66GHz i7 MacBook Pro at single threaded tasks, about 5% faster than the 2.8GHz i7 at single-threaded tasks. The Geekbench scores are only so much higher because of the multithreaded tasks, because the Mac Pro here had THREE TIMES as many cores as the MacBook Pro, which is a dual-core machine.
     
  12. raymondthimmes macrumors member

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    Columbus, Ohio
    #12
    so an i7 versus a core 2 duo is still a competition between clock speeds?

    Well, this solves my dilemma concerning which macbook to buy
     
  13. NickZac macrumors 68000

    NickZac

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    #13
    I would imagine this will change pretty quickly as more and more tasks become multis and the multi-core CPU gains the abilities to do things which were not thought possible and through this increases the speed on single threaded tasks.
     
  14. Hellhammer Moderator

    Hellhammer

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    #14
    No. They use different microarchitecture so comparing clock speeds is more or less useless. i7 supports things like Hyper-Threading and Turbo while C2D does not. You should look at benchmarks such as GeekBench and some real world stuff like HandBrake
     
  15. NickZac macrumors 68000

    NickZac

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    #15
    In grossly un-technical layman's terms, the i7 can run faster than it is rated with certain resource-heavy processes through a blanket process commonly called 'overclocking' where as the CoreDuo and Core2Duo designs do not have this feature.
     

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