DDR3 v GDDR5

Discussion in 'iMac' started by Macginger, May 7, 2011.

  1. Macginger macrumors member

    Macginger

    Joined:
    Jul 20, 2010
    Location:
    Wiltshire, United Kingdom
    #1
    Hey all

    Would the 1333MHz DDR3 SDRAM be a bottle neck for the Radeon 2GB GDDR5?

    sorry if this sounds dumb to some but it's something that just doesn't look right to me :confused:
     
  2. Hexley macrumors 6502a

    Joined:
    Jun 10, 2009
    #2
    If that's the case then Sandy Bridge is the bottleneck as well.
     
  3. TMRaven macrumors 68020

    TMRaven

    Joined:
    Nov 5, 2009
    #3
    There's always going to be a bottleneck no matter what, but no the ram will not hinder your gaming performance as much as you're thinking. 2gb of vram is more than enough of a buffer.
     
  4. Badger^2 macrumors 68000

    Badger^2

    Joined:
    Oct 29, 2009
    Location:
    Sacramento
    #4
    System RAM has no relation to the ram on the video card.
     
  5. Macginger thread starter macrumors member

    Macginger

    Joined:
    Jul 20, 2010
    Location:
    Wiltshire, United Kingdom
    #5
    Thank you guys, thats put my mind to rest, much appreciated
     
  6. Hellhammer Moderator

    Hellhammer

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    Dec 10, 2008
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    Finland
    #6
    Your GDDR5 in 6970M runs only at 900MHz. Memory bandwidth is 115.2Gb/s whereas 1333MHz DDR3 in dual-channel offers up to 170.6Gb/s.
     
  7. TMRaven macrumors 68020

    TMRaven

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    Nov 5, 2009
  8. Hellhammer Moderator

    Hellhammer

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    #8
    Ahh damn it. I guess I saw the memory bandwidth on AMD's site as Gbits, although there is a big B indicating bytes.
     
  9. TMRaven macrumors 68020

    TMRaven

    Joined:
    Nov 5, 2009
    #9
    AMD's site? Now I'm confused. Are we talking memory bandwidth of the cpu vs gpu?
     
  10. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #10
    RAM (21.3GB/s) vs GPU (115.2GB/s) memory bandwidth. AMD=ATI. I thought the 6970M's mem bandwidth was in Gbits when I first looked, thus the confusion.
     

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