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gpu x8 not x16

Discussion in 'Graphics Cards' started by blindrage, Feb 6, 2013.

  1. blindrage New Member

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    im running gtx 660 ti on a z77a-gd65 msi board . when i use gpu-z it showes my gpu running @ x8, so i ran the test to see if it would kick in to 16x and it did not. any suggestions
     

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  2. Crap Daddy

    Crap Daddy

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    First pci-e slot?
     
  3. lyndonguitar

    lyndonguitar I play games

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    The specs on his mobo says three times x16

    edit: i didn't quite understood the specs site. the basic specs said... Gen3 (16, 8, 4), while the detailed specs mentions 3 x PCIe 3.0 x16 slots only, no mention of 8x/4x mode

    oh well nvm
     
    Last edited: Feb 6, 2013
  4. blindrage New Member

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    yes it is pci x16 x3 3.0
     
  5. terrastrife New Member

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    the board is, 8/8/0 or 8/4/4. there is no physical 16x link.
     
  6. TRWOV

    TRWOV

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    socket 1155 Ivy Bridge CPUs only have 16 PCIe 3.0 lanes so if you go SLI you get 8/8. The chipset has 8 extra PCIe 2.0 lanes (4 1x slots + 1 4x slot).
     
    Crunching for Team TPU
  7. gdallsk

    gdallsk

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    your chipset only supports up to 16 lanes of PCI-Express, the rest is reserved for your peripherals and so on. You would not have had more lanes unless your board is equipped with a PLX chip which I don't think it is...
     
  8. terrastrife New Member

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    ^uhh guys you two, the board doesn't have a 16x slot at all. it has an 8/8/0 or 8/4/4 layout.
     
  9. gdallsk

    gdallsk

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    it has, they are halved as you have two cards in your PC
     
  10. terrastrife New Member

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    there is no 16x electrical link to a single slot on this board.
    the first blue slot is hardwired as 8x
    the second slot is hardwired as 8x but has switches to swap 4 lanes to
    the third slot with is hardwired as 4x

    I am guessing this was done as PCIE 3.0 switches are expensive, and this, being a mid range board, they would rather save money.
     
  11. gdallsk

    gdallsk

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    Seriously? A mid-high end board with an x8 main PCI-Express? You're kidding right?
     
  12. terrastrife New Member

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    Well it is PCIE 3.0 so it's the same performance as a 16x PCIE 2.0 slot.

    But having a look at the photos of this board close up, the specs and the hardware layout on the motherboard don't match up. I was taking my information from text, which may be based on an older or reviewer board.

    Looking at the board itself it has hardware for 16/0/0 in addition to 8/8/0 and 8/4/4, but there is also the possibility the BIOS is limited.
     
  13. gdallsk

    gdallsk

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    that is more likely...
    But seriously, nobody in a heck's name would ever put a single PCI-Express on x8 on a single card for the first slot in this stage of time...
    The OP has two cards and I quote "two" cards, that is why his lanes are split.
     
  14. terrastrife New Member

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    They should, I'm pretty sure most people would pick saving say, $25 (or more) on a motherboard because with a single card you really aren't going to notice a difference, and with two, it's just the same (or better as there is no latency or any other issues involved with switches).
    Of course, if you had a PCIE 2.0 video card you would probably see a few percent drop in performance.
     
  15. Crap Daddy

    Crap Daddy

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    This. By the specs he runs SLI, therefore he has 2 x 8.
     
    gdallsk says thanks.

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