Solved

PCIe Configuration question

As a Newbie I need confirmation of my interpretation of the following PCIe 16 configuration:
Slot No. 2: PCIe 3.0/2.0 x 16_1 slot (Single at x16

or dual at x8 / x8 mode)

Slot 5: PCIe 3.0/2.0 x16_ 2 slot (single at x16 or

dual at x8 / x8 mode)

Slot 7: PCIe 2.0 x16_3 Slot (at x4 mode)

1. Only one PCIe 16 lane Card running at x16 speed possible;
2. If 16 LAne Card is in Slot 2, then no card allowed in Slot 5;
3. If no PCIe 16 lane Card is used then 2 PCIe one,four, eight, or 16 lane cards can go in Slot 2 and Slot 5, one per slot running at x8 speed.
4. Slot 7 will accept a 1,4,8,or 16 lane Card running at x4 speed.

Is that correct ?
13 answers Last reply Best Answer
More about pcie configuration question
  1. Your motherboard model would help.

    Because depending on your mobo it is possible to run 16x + 16x +8x with EVGA X79 Classified at the same time so depending on the mobo.
  2. serenatous said:
    Your motherboard model would help.

    Because depending on your mobo it is possible to run 16x + 16x +8x with EVGA X79 Classified at the same time so depending on the mobo.


    Thnak you for your quick response: MOBO is Asus P8Z778-V LK
    Is that not what I said in my #3 interpretation ?
  3. According to the motherboard specs: PCie 3: 2 (x16/0 or x8/x8)

    I think it means that you can run:

    pcie 3.0 16x 16x
    or
    pcie 3.0 8x 8x which = to pcie 2.0 16x + 16x


    Hope this helps :)

    I am not sure if this answered your question or if that is the answer you are looking for if not please do clarify what exactly are you trying to find out.
  4. serenatous said:
    According to the motherboard specs: PCie 3: 2 (x16/0 or x8/x8)

    I think it means that you can run:

    pcie 3.0 16x 16x
    or
    pcie 3.0 8x 8x which = to pcie 2.0 16x + 16x


    Hope this helps :)

    I am not sure if this answered your question or if that is the answer you are looking for if not please do clarify what exactly are you trying to find out.


    Do you mean . One PCIe 16 Card running at x16 speed in Slot_2 with Slot_5 empty vs A PCIe 8 Card running at x 8 Speed in in Slot 2 and another PCIe 8 Card running at x 8 speed in Slot5 ? In that case my interpretations 1 through 4 should be correct ??
  5. This will explain how pcie should look like, and what speed it is:
    http://linuxtidbits.files.wordpress.com/2009/01/pci-express-slots.gif?w=560


    Now when you look at your mobo:
    http://www.asus.com/websites/Global/products/J4TfLoZ8TXyFAkFb/kGbPoHZWumX35DVV_500.jpg


    Now the blue and the white slot are 2 x PCIe 3.0/2.0 x16 (x16 or dual x8) which means, that you can have 2 cards running at 16x pcie 3.

    Or encase you have pcie 2 then 2 cards running at 8x pcie 3 since pcie 3 is backwards compatible with pcie 2.

    So Pcie 3 running at 8x is = to Pcie 2 at 16x


    Now the 2 small blue ones, above and under the blue pcie 3 16x, are pcie x1 slots.


    Now the black one is the last one on the bottom it is a pcie 2 16x, will run at x4 speed, as in that is the maximum speed it will run at.

    Hope this helps :-)


    Ops i forgot to tell you about the 2x light blue ones those are pci slots not pcie.

    so 2 x light blue = pci slots.

    Hope this helps :-)
  6. Best answer
    serenatous said:

    Now the blue and the white slot are 2 x PCIe 3.0/2.0 x16 (x16 or dual x8) which means, that you can have 2 cards running at 16x pcie 3.

    Or encase you have pcie 2 then 2 cards running at 8x pcie 3 since pcie 3 is backwards compatible with pcie 2.


    This is just completly wrong.

    OP you were correct in what you stated originally. if you put in one GPU it will run at x16. if you put a card in both x16 slots they will both run at x8. you could never run 2 cards at x16. And if you put in 2 pcie 2.0 cards its going to run at pcie2.0x8 NOT pcie3.0x8


    if you have a sandy bridge CPU, or a pcie 2.0 graphics card its going to run at pcie 2.0 speeds. if you have ivy bridge and a pcie 3.0 card it will run pcie 3.0 speeds.
  7. I did some more digging on it and i apologize to the op.

    "The board features three PCIe 3.0 16x that fully supports the Gen3 GPU, this can be run by a single x16, dual x8/x8 and triple 8x/4x/4x multi GPU configurations. In between of these there's a four PCIe x1 slots."

    I misunderstood the specs of the mobo my bad.
  8. there are 2 slots, but ivybrudge and sandy bridge only have 16 pcie lanes to split between them. to run pcie 3.0 you have to have ivy bridge and a 3.0 card
  9. unksol said:
    there are 2 slots, but ivybrudge and sandy bridge only have 16 pcie lanes to split between them. to run pcie 3.0 you have to have ivy bridge and a 3.0 card



    Ah okay :) thank you for the correction :)
  10. Best answer selected by rustaub.
  11. unksol said:
    This is just completly wrong.

    OP you were correct in what you stated originally. if you put in one GPU it will run at x16. if you put a card in both x16 slots they will both run at x8. you could never run 2 cards at x16. And if you put in 2 pcie 2.0 cards its going to run at pcie2.0x8 NOT pcie3.0x8


    if you have a sandy bridge CPU, or a pcie 2.0 graphics card its going to run at pcie 2.0 speeds. if you have ivy bridge and a pcie 3.0 card it will run pcie 3.0 speeds.
  12. unksol said:
    This is just completly wrong.

    OP you were correct in what you stated originally. if you put in one GPU it will run at x16. if you put a card in both x16 slots they will both run at x8. you could never run 2 cards at x16. And if you put in 2 pcie 2.0 cards its going to run at pcie2.0x8 NOT pcie3.0x8


    if you have a sandy bridge CPU, or a pcie 2.0 graphics card its going to run at pcie 2.0 speeds. if you have ivy bridge and a pcie 3.0 card it will run pcie 3.0 speeds.

    Thank you for clarifying the issue. Appreciate it.
  13. Forgot to ask: Who is "op," ? ?
Ask a new question

Read More

Configuration Components