SSE4 instruction set for Penryns

Discussion in 'Mac Pro' started by bimp, Jan 9, 2008.

  1. bimp macrumors newbie

    Joined:
    Jan 9, 2008
    #1
    I'm not techie enough to understand the implications of this - although from what I've read this is what helps speed things up in the Penryns along with the better architecture, faster bus speeds etc....

    My questions is will existing software need to be recompiled to make full use of the Penryn and SSE4, or will it run just fine? In partcular, I'm thinking of the 3D rendering application Maxwell. If I buy a new Mac PRO will I have to wait for a new release of the application?

    Any enlightenment will be greatly appreciated.

    Thanks.
     
  2. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #2
    Existing apps won't stop working just because of the existence of new instructions. But they won't use them either so you will not get any boost from the SSE4. Note some apps may already be compiled to check for SSE4 and use it if it's available: check with the manufacturer/author.
     
  3. bimp thread starter macrumors newbie

    Joined:
    Jan 9, 2008
    #3
    Thanks for the quick reply Robbie.

    Have I got this straight then - the app will most likely work fine, but the speed increase will only be due to faster bus speed, clock speed, more cores, and not because the app uses the SSE4 instructions.

    But, as I understood it, Penryns use SSE4 only. So if the app doesn't use the SSE4 - what's it using in the chip?

    I've asked this question on the app forum too, but have got no reply yet.

    I'm so confused.
     
  4. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #4
    Your understanding is 100% wrong. SSE (in all flavours and MMX as well) are extensions to the standard x86 instruction set. All normal x86 instructions are present and can be used by apps. In addition MMX and SSE1,2 & 3 instructions are still available for use.
     
  5. bimp thread starter macrumors newbie

    Joined:
    Jan 9, 2008
    #5
    Got ya, understanding dawns, slowly.

    Thanks for clearing that up Robbie.





    I am definitely a case of a little bit of misunderstood knowledge, with absolutely no understanding, jumping to ridiculous conclusions. :eek:
     
  6. deathshrub macrumors 6502

    Joined:
    Oct 30, 2007
    Location:
    Christmas Island
    #6
    Don't be so hard on yourself. :)

    If you buy one of the new Mac Pros, it will be a monster of a machine and serve you very well for years to come.
     

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