turbo boost on westmere vs nehalem

Discussion in 'Mac Pro' started by Ravich, Aug 13, 2010.

  1. Ravich macrumors 6502a

    Joined:
    Oct 20, 2009
    Location:
    Portland, OR
    #1
    Is the westmere's turbo boost better? I heard someone say that it is and I wanted to confirm.
     
  2. CaptainChunk macrumors 68020

    CaptainChunk

    Joined:
    Apr 16, 2008
    Location:
    Phoenix, AZ
    #2
    I'm pretty sure that TurboBoost is no different on the Westmere cores. They're merely die shrinks of the Nehalem cores with a new AES instruction set. And AES's functionality is limited to handful of applications used for data encryption.
     
  3. Hellhammer Moderator

    Hellhammer

    Staff Member

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    Dec 10, 2008
    Location:
    Finland
    #3
    Depends on what chips you are comparing. Nehalems (Bloomfield) have 1/1/1/2 Turbo (explained later) while W3680 (used in 6-core MP) has 1/1/1/1/2/2 Turbo, so not much better. However, the X5650 and X5670 used in 12-core Mac Pro have 2/2/2/2/3/3 Turbo.

    The W3530 has frequency of 2.8GHz. When 4, 3 or 2 cores are used, it can only boost ONE multiplier as shown above, resulting a clock speed of 2.93GHz. When only one core is used, it can boost by two multipliers, i.e. up to 3.06GHz. So, the W3680 isn't much better as it can only boost two multipliers which is the same as in Nehalem but the Westmere-EP (used in 12-core MP) can boost more, by two multipliers with 3-6 cores in use and up to 3 multipliers when 1-2 cores are in use.

    To summarize, the 12-cores have more aggressive Turbo than others. Sorry for confusing post, feel free to ask if you have anything. It's not that easy to make it simple if Turbos for all cores are taken into consideration.
     
  4. eponym macrumors 6502

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    Jul 2, 2010
    #4
    That's an awesome explanation! I wondered how that all worked. :)
     
  5. jjahshik32 macrumors 603

    Joined:
    Sep 4, 2006
    #5
    I'm curious if the 6 core Mac Pro has two multipliers as well.
     
  6. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #6
    2x multiplier when one or two cores are used. 3-6 is 1x multiplier. If more than 6 (AKA 7-12 HyperThread "cores") then there is no turbo boost.

    I would add the reason the 12-core models have higher turbo because they have lower TDPs. The X5600 units run at 95W (so they have more leeway to turbo more) while the W3600/W5600 units run at 135W.

    So by that the 8-core processors (dual processor) from the 2009 models also had more aggressive turbo boost than their 4-core (single processor) counterparts by running at lower TDP.
     
  7. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
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    Finland
    #7
    Good point

    The low-end 8-core had no aggressive Turbo, just 1/1/1/2 but 2.66GHz and 2.93GHz 8-core had 2/2/3/3 Turbo. The E5520 is 80W while X5550 and X5570 are 95W chips though, that might make the difference.
     
  8. The Beatles macrumors regular

    Joined:
    Jun 16, 2010
    #8
    Yeah, it made me feel smart.

    I realized i was "getting it" when i noticed my eyes starting to glaze over yet i was still digesting the info, i was able to hold on till the end and before my brain shut down.
     
  9. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #9
    The Exxxx parts are all their mainstream models whereas the Xxxxx models are their high-end models. Hence the crappy turbo boost on the quad core Westmere.
     
  10. Niner macrumors newbie

    Joined:
    Aug 26, 2008
    #10
    single 6 core or 2 quad cores (both westmere)

    So with the turbo boost multipliers, would it be better/worse to get the single 6 core processor at 3.33GHz or to get the two 4 core processors at 2.4GHz?

    They're only a few hundred bucks either way, so I need some help :D
     
  11. Tutor, Aug 17, 2010
    Last edited: Aug 28, 2011
  12. CaoCao macrumors 6502a

    Joined:
    Jul 27, 2010
    #12
    Still isn't as fast as my Pentium 4 EE 3.73 GHz
    :cool:
    I use it in a Dell workstation to play exactly 1 game from 2005
     

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