SLI Problem + Maximus V Extreme (Black PCIe Slot)

Discussion in 'Videocards - NVIDIA GeForce' started by Hav0q, Sep 15, 2013.

  1. Hav0q

    Hav0q Master Guru

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    So this is frustrating me.

    Optimally for airflow, I want to use the black PCIe slot of my Maximus V Extreme...but when I install my second video card, it doesn't detect it. I've messed with all the Preset settings in the bios (also tried different Gen1,Gen2,Gen3 modes) and no dice. Any ideas?
     
  2. Hav0q

    Hav0q Master Guru

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    So I had to remove my Creative Titanium HD and boom, second card is now being identified and running at native 8x speed (vs PLX)...I guess I have to find another audio solution other than onboard...just not sure what/how?
     
  3. PhazeDelta1

    PhazeDelta1 Moderator Staff Member

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    That board has a x4 slot, so stick the sound card in it. Put your GPUs in the 1st and 3rd slot.
     
  4. Hav0q

    Hav0q Master Guru

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    I had it that way initially and it all worked BUT the secondary video card was running in 8x PLX mode instead of native...now in the black 2B slot it runs 8X native and it's much smoother (I see no microstuttering at all). I'm in kind of a bind as to what to do. Maybe a newer sound card is PCIE 3.0 compliant? Not sure on that.
     

  5. Megabiv

    Megabiv Master Guru

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    Have a look in the manual (I know I know..) and see if it mentions any specific configurations to use when running multiple GPU's and PCI-E cards.

    For example my X58 Sabertooth has 3x PCI-x16 slots. It will happily run slots 1 + 2 at x16 and slot 3 at x4 (but only at x1 if another PCI-E slot it used).
     
  6. keromyaou

    keromyaou Member Guru

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    I use Asus Maximus V Extreme myself. I have two Titans in slot 1 and 4 (native PCI-E). And I also have a Asus Xonor audio card in 4xPCI-E lane (slot 6). They all work fine. GPU-Z recognizes as two 8xPCI-E (ver 3.0). I don't know in which lane you exactly put your audio card. But at least for me, this configuration works fine.
     
  7. Hav0q

    Hav0q Master Guru

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    Haha, I did. It recommends me to set it up the way I have it now for Native performance. What it doesn't tell you is that if you use another card in the PCIe slots, it'll break it.

    I did that but then card 2 is running in PLX and slower, micro stuttering is in effect.
     
  8. keromyaou

    keromyaou Member Guru

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    I see. Interesting. How did you detect if PLX is being used or not? Are you sure that there are definitely differences between two 8xPCI-E (native) only and two 8xPCI-E (native) plus one 4xPCI-E in terms of micro stuttering?

    According to Wikipedia, Z77 board has main PCI-E lanes and secondary PCI-E lanes (http://en.wikipedia.org/wiki/LGA_1155). The main PCI-E lanes are either 16x1 or 8x2 (3.0) while the secondary lane is 8x1 (2.0). I thought that the 4xPCI-E lane (3.0, slot 6) was based on the secondary PCI-E (2.0). I don't know precisely how PLX works for the main and the secondary PCI-E lanes. If Z77 board has one 16xPCI-E (3.0, main) and one 8xPCI-E (2.0, secondary) natively, I don't think that PLX is required for two 8xPCI-E (3.0) and one 4xPCI-E (3.0) configuration.
     
  9. Hav0q

    Hav0q Master Guru

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    Yeah, my BIOS let's me know if it's running in native or PLX mode (which is really nice). I can see a difference with FPS style games for sure, it is much smoother when running native 8x mode. I also ran GPU-Z and realized the BIOS' are different from both of my cards (lol). One runs at a higher vcore too. I'm not sure if I should flash them to be identical or not.
     
  10. keromyaou

    keromyaou Member Guru

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    I see. I am curious. Could you let me know which BIOS can provide the information about PLX mode?

    I also found this article (http://www.anandtech.com/show/6170/...x-8747-featuring-gigabyte-asrock-ecs-and-evga). Please look at the first diagram. 16xPCI-E connectors are directly connected with CPU socket. Meanwhile there are four 1xPCI-E for peripheral devices and one 4xPCI-E for 4xPCI-E (2.0) connector, which are connected to CPU socket through Intel Z77 controller. As far as I understand from this article, PLX works as a switch between 16xPCI-E connectors and CPU socket, which is nothing to do with Intel Z77 controller. The 4xPCI-E (2.0) lane (slot 6) is most likely the one which is connected to Intel Z77 controller. Then occupying this 4xPCI-E lane with an audio card shouldn't have impacts on 16xPCI-E (3.0) lanes (in the same way as occupying 1xPCI-E lanes which are connected to Intel Z77 controller shouldn't have impacts on 16xPCI-E lanes).

    If your BIOS shows that PLX is working for the 2nd gpus when 4xPCI-E lane is occupied, I feel that there must be the way to avoid this. In this sense the updating the BIOS for your gpus (or maybe updating drivers for your audio card, and so on) might be worthwhile.
     

  11. JJayzX

    JJayzX Master Guru

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    The cpu only has 16 lanes available and uses the plx to add more. The sound card also doesn't necessarily need to be 3.0 also.
     
  12. Hav0q

    Hav0q Master Guru

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    I figured out a work around...well, not really-I knew it would work I was just avoiding it. I just have to install the video cards in slot 1 and 2B (red/black) and install the sound card in the 4x slot (which gives no room between video card in 2B) which brought my temps up a little but I guess I'll live with it until I pick up some waterblocks.

    The bios feature is:

    Extreme Tweaker\GPU.DIMM Post:

    [​IMG]

    Pardon the ****ty picture.
     
  13. keromyaou

    keromyaou Member Guru

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    I am glad to know that you resolved the issue. I do water cooling for both cpu and gpu. I checked out that running games do not increase PLX temperature (around 36-38C), confirming that PLX is not in use.
     

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