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Is there mother board that supports 4 PCIE 3.0 x 16 of 4 lanes "True 16"

I am currently running R9 290x in crossfire and want to upgrade my board to get full bandwidth.
The only card I can find is asrock X79 Extreme11. I wanted to know if there are any other boards if you want to furture proof with 4 lanes.. ?
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More about mother board supports pcie lanes true
  1. Ozzmodious said:
    I am currently running R9 290x in crossfire and want to upgrade my board to get full bandwidth.
    The only card I can find is asrock X79 Extreme11. I wanted to know if there are any other boards if you want to furture proof with 4 lanes.. ?


    No consumer board supports 4 x 16 PCIe 3.0 because there's no platform available that exposes that many lanes.

    The most capable design is the LGA-2011 socket which exposes 40 PCIe 3.0 lanes, which can be configured as 3 x 16 at best. The X79 PCH exposes another 8 PCIe 2.0 lanes, but these are often gobbled up by peripherals.

    There are server boards from vendors such as Asus and Supermicro that expose 4 or more full 16x slots but these draw lanes from more than one CPU socket, and thus require more than one Xeon E5-2000 series CPU or above to be installed
  2. Thankyou for the quick reply. So what boards support PCIE 3.0 x 3? Asrock say its true 16 over 4 lanes? But your saying no single chip can handle that correct?

    http://www.asrock.com/mb/Intel/X79%20Extreme11/
  3. Ozzmodious said:
    Thankyou for the quick reply. So what boards support PCIE 3.0 x 3? Asrock say its true 16 over 4 lanes? But your saying no single chip can handle that correct?

    http://www.asrock.com/mb/Intel/X79%20Extreme11/


    That's correct. No single chip can handle it. What some motherboards do is use a PCIe bridge multiplexer to split a 16x lane into two. Under full load conditions each will have only half the bandwidth, so it is not a "true" pair of 16x lanes.
  4. Pinhedd said:
    Ozzmodious said:
    Thankyou for the quick reply. So what boards support PCIE 3.0 x 3? Asrock say its true 16 over 4 lanes? But your saying no single chip can handle that correct?

    http://www.asrock.com/mb/Intel/X79%20Extreme11/


    That's correct. No single chip can handle it. What some motherboards do is use a PCIe bridge multiplexer to split a 16x lane into two. Under full load conditions each will have only half the bandwidth, so it is not a "true" pair of 16x lanes.


    What about the asrock then?
  5. Best answer
    Ozzmodious said:
    Pinhedd said:
    Ozzmodious said:
    Thankyou for the quick reply. So what boards support PCIE 3.0 x 3? Asrock say its true 16 over 4 lanes? But your saying no single chip can handle that correct?

    http://www.asrock.com/mb/Intel/X79%20Extreme11/


    That's correct. No single chip can handle it. What some motherboards do is use a PCIe bridge multiplexer to split a 16x lane into two. Under full load conditions each will have only half the bandwidth, so it is not a "true" pair of 16x lanes.


    What about the asrock then?


    That motherboard uses a pair of 48 port PLX PEX 8747 PCIe switches to dynamically multiplex root port access. In short, it allows motherboard vendors to take a single 16x PCIe 3.0 link from the CPU and splits it into two 16x PCIe 3.0 links (for a total of 48 bidirectional links) or four 8x links. As a consequence, neither link will have a full 16x PCIe 3.0 worth of dedicated bandwidth to the root port, they can still collide if both devices make requests at the same time but the switch will deal with the collision. This makes for better overall utilization than splitting the 16x link into two 8x links which cannot share bandwidth. Mathematically this can be described as a form of multiplexing gain. It's as close to 4 "true" 16x lanes as one can get without having a multi-socket system.

    According to that motherboard's datasheet, when all 7 PCIe slots are populated, only the first slot runs at 16x, the rest all run at 8x.
  6. Thanks for the help. Im going to test that board with CF and see the difference. I'm currently running CF

    Z68X-UD3H-B3 which runs at PCIE 2.0 x8
    2500K
    Lepa 1600W
    1600 DDR3 16Gig
    OCZ 120
    3 1 TB Drives
    But I want the most out of my cards. Possibly 3 or 4 way in future.
    Upgrading CPU to I7 4930K
  7. There site and Paul on Newegg and Linus all say it supports full 16 on lanes 1,3,5,7. So I guess I answered my own question... No there is no other board like this one.
  8. Ozzmodious said:
    There site and Paul on Newegg and Linus all say it supports full 16 on lanes 1,3,5,7. So I guess I answered my own question... No there is no other board like this one.


    It does support full 16 on 4 lanes at once, but it does so through a switch. It's the same idea behind multiple PCs on a home network all being connected over gigabit NICs. Each of the PCs can utilize the full gateway bandwidth, but if more than one PC sends or receives traffic from the gateway the switch will have to arbitrate access.

    If both cards on the PCIe switch make requests at the same time for a sustained duration, the effective bandwidth will fall to PCIe 8x speed (or more appropriately, approximately PCIe 16x 2.0 speed). Fortunately most bus traffic tends to be bursty rather than sustained, so these kind of bridge chips work pretty well.
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