Anyway around the 1gb vram buffer?

Discussion in 'Videocards - AMD Radeon' started by Brandon_34, Dec 11, 2011.

  1. Brandon_34

    Brandon_34 Master Guru

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    I have an idea but I don't know if it wll work.

    I have a 5970 2gb and was thinking if I get a 5870 2gb card and put it in the top pci-e slot and put the 5970 in the bottom slot will I be able to get full 2gb of vram usage from the 5870 or will it get locked to 1gb of vram?
     
  2. BlackZero

    BlackZero Ancient Guru

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    I'm afraid memory has to be mirrored for all multi-gpu configurations on a per gpu basis with each gpu having it's own memory partition so there's no way around it, as of yet.
     
  3. Brandon_34

    Brandon_34 Master Guru

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    Man that really stinks. Thanks for the info:)
     
  4. Agent-A01

    Agent-A01 Ancient Guru

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    yep sorry; also if you want an extra bit of vram in games, 40-100mb go to the games properties and disable desktop composition and visual themes
     

  5. BlackZero

    BlackZero Ancient Guru

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    That's a good idea, even with a 2Gb card I might find myself having to do that with skyrim fully modded :giggle2:
     
  6. Agent-A01

    Agent-A01 Ancient Guru

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    yeah i became into the habit of doing it :p since vista
     
  7. k3vst3r

    k3vst3r Ancient Guru

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    only way is new card with bigger VRAM unfortunately
     
  8. k1net1cs

    k1net1cs Ancient Guru

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    Or you could try butchering other cards' memory chips (of higher density), and use them to replace the ones in your 5970 so that it could have 3 or even 4GB with a few soldering here and there. :p
     
  9. wlw_wl

    wlw_wl Master Guru

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    Care to explain? I thought 2GB + 2GB = 2GB CF, isn't it like that?
     
  10. AdamPI

    AdamPI New Member

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    Yeah, but the 5970 he has is a dual GPU card, so it in this case with the 2GB 5870 it would be more like:

    1GB + 1 GB + 2GB = 1GB CF

    If you could disable crossfire on the 5970 and have it assign it's full 2GB to one core, that would enable the proposed set-up to have Xfire 2Gb or Tri-fire 1Gb, but you can't.
     

  11. Brandon_34

    Brandon_34 Master Guru

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    no you have 2 gpus on a 5970 with 1gb each. 1 GB is effective while the other gig just contains the same data.

    I was hoping that getting a 5870 2gb eye infinity 6(which is a single gpu) card and making it the master gpu that games would use the full 2gb of vram but I guess that won't work which I think is retarded but oh well.
     
  12. Norezar

    Norezar Active Member

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    Talk about hardmode.
     
  13. Pill Monster

    Pill Monster Banned

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    I don't think mirrored data applies with dual GPU cards.
    I'm pretty sure it only takes effect when the vram is on separate cards.

    In other words; if you have one card with 2 GPU's and the vram on that card is not split into 2 halves, the 2 GPU's can access all the memory.

    Therefore he would have 2GB of vram available....not sure tho, so will double check...


    Edit:
    nvm I can't find the info I wanted ,so take my comment with a grain of salt...
     
    Last edited: Dec 12, 2011
  14. Agent-A01

    Agent-A01 Ancient Guru

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    its still mirrored. each card has its own set of memory chips.
     
  15. Pill Monster

    Pill Monster Banned

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    Yeah I'm not disputing that; I was saying the vram on one card shouldn't be halved, unless each 2GB vram is really 2x 1GB channels & each GPU can only access one channel

    So.... 2x 2GB dual GPU cards in CFX = 2GB available, not 1GB available...(assuming both GPU's have access to all vram on one card).

    If that makes sense...
     

  16. Agent-A01

    Agent-A01 Ancient Guru

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    Right, each gpu has 1gb dedicated per channel. The card is limited to 1GB of vram, the other 1gb is mirrored. so it is 1GB available
     
  17. Ti3Kob

    Ti3Kob Master Guru

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    One card or two it doesn't change anything, it's still Xfire. The memory is dedicated to one GPU, and can't be shared. You'll need to divide the total amount of memory by the number of GPUs, independently of how many physical cards you have in the system (assuming all GPUs have the same amount of dedicated memory, else it's limited to the smallest available). The 5970 2GB has 1GB dedicated per GPU, mirrored. The 5970 4GB however has 2GB per GPU, like the 6990.
     
    Last edited: Dec 13, 2011

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