Computer not recognizing second video card

Thanks in advance for anyone who takes their time to help.

( built this computer myself about a month ago using new/old parts )
System specs:

OPERATING SYSTEM:Windows (Service Pack 1)
Cpu : intel® Core™ i7-3820 CPU @ 3.60GHz
Mobo : P9X79 pro
Psu: 600 watts ( I had to send my corsair 850 watt in for repair since it blew on me a couple days ago, ripped my 600 watt out of old pc to keep everything running till it returns.)
( newst drivers)

Issue : I salvaged my old pny geforce 460 gtx out of my old rig and was using it in my new one with no issues. Today I installed a evga geforce 460 gtx ( both 1gig) hoping to run SLI ( i connected both using the sli brdige that came w/ my mobo, and installed it in the second pci-e 16x slot) BUT my computer is only recognizing 1 of the cards.

attempts made to fix : I've tried both cards in the first pci-e 16x slot and both of them work alone. Ive gone on nvidias website and ran their driver updater which removers old drivers and automatically updates my new drivers.

The fans work for both cards so I know the second one is getting power but when I go to the device manager I only see one card under the display adapters. Ive also tried running this driver finer program someone linked on this forum but it doesnt have the lga 2011 boards on it.

Thanks again. This is the first time I've made a post so If you need anymore info let me know.
25 answers Last reply
More about computer recognizing video card
  1. Also looked through the bios but there was nothing related to enabling or disabling pci slots.
  2. both card need 2 power cable of 6 pins with at lest 24 amp on 12 volts see if they both receive power,you could try to switch card 1 to slot 2 and card 2 to slot 1 the using the could aslo check one card at the time in both slot to see if they work or the second slot of the motherboard is not defective
  3. I have a couple questions;
    1 in the list of components you have the video card memory as 3.97gb and later in your post you say that both GTX 460's have 1gb of ram ?
    2 The video card driver nvd3dum.dll , what driver is that?
    3 you didn't list your motherboard.

    When you have both cards in the board you do have the power cables connected to both cards?
    When putting the cards in and removing them is the power supply unpluged ?
  4. The video card memory was some stat that blizzards system checker picked up I guess.

    not sure what driver that is. Got that info from the same as above

    And my mobo is p9x79 pro. ( Thought I put that, woops)

    Right now the Psu I'm temp using doesn't have two separate 6pin cables so I have the two 6pin cables in the top card, and then I have two 6pin power adapters hooked up into the bottom one ( the two 6 pin adapters plug into the slots and then are connected to 4 of those 4 hole power connectors that went to hard drivers and fans)

    both video cards currently have fans running and when plugged in solo both work. The cards don't work independently when plugged into the other pci-e 16x slot tho and the computer will run with no video.

    I turn the power supply switch off and wait 30 secs but I don't unplug it.

  5. since you board is having 4 pci-e slot could you try a card in slot 2 then in slot after in slot 4 if only slot 1 work with a graphic then the board could be efective on the graphic slot also you power could be not able to handle both card at the same time
  6. If the fan on the card is working does that mean its fully powered or just that it has enough to enable that function? Also Is my computer going to recognize it in the other slots if it was recommended to use the 1st slot for gpu's?
  7. when you put them in first slot with power cable and have signal send to monitor then they work do the same for the other pci-e slot
  8. So when I plugged the first one into the pci-e 16x _1 slot and the second card in the pci-e 16x ( at 8x mode) slot it recognizes both of them. However the pci-e x16 ( dual at x16 /x16) slot doesn't recognize the 2nd one.

    Does this mean my mobo is defective or that I have overlooked something like enabling it or the graphics cards not functioning at 16x/16x ?

    This is only the 2nd computer Ive built from scratch so I'm still nub at a lot of the obvious stuff.
  9. Out of curiosity do you have your SLI bridge connected? IDK if that would cause the other card to not be recognized, as I have no experience with SLI or XFIRE.
  10. Did you go into Nvidia Control Panel and look for the option to enable SLI?
  11. I've always had the bridge connect except when I hooked up the single card to the bottom pci-e 16x slot.

    and there has never been an option in the nvidia panel for enabling sli. Ive seen screen shots of what everyone elses control panel looks like but mine doesnt have that option ( which is a huge area of my frustration )
  12. SO both video cards are being recognized with my cards plugged into the pce-e 16x sloit and pci-e 16x (dual 8x slot) but sli is not an option. uhg.
  13. There is defietly something funky going on here , so now you have it to where both cards are recognized in device manger and when you go to the Nvidia control panel do you also see both cards? If both are there and the sli bridge is connected there is no option to enable SLI ?
    What driver version are you using? If you don't know how to get it , you go to device manager and right click on the card and select properties then the driver tab and the last 5 digits are the driver version. Also in the Nvidia control panel you select help at the top of the window and select system information and that will give you the driver version and all the other info on the card.
    If you haven't already tried it you should uninstall everything , drivers , cards , everything video and then reinstall using the cd that came with the card and before updating the drivers see if it works , see if you can enable sli and see if both cards are recognized.
  14. driver version for both the cards. one is labeled nvidia gefroce GTX v2 and one nvidia geforve GTX.

    And so Other then uninstalling the two videos cards drivers what other ones should I?
  15. You would only need to be concerned with the video card drivers.
  16. this is to find if your sli brige is working
  17. Flashed my bios to the newest version, then uninstalled my 2 video cards and restarted with them in the two pci-e 16/16 slots but the second 16x slot card is still not popping up.

    as far as the bridge goes, I'm not even worrying about that till I get my friggin cards actually recognized. and I do have a 3 way bridge If thats fine to use with 2 cards.
  18. did you test you sli bridge
  19. You cannot use the three way bridge for two cards , you have to use the ribbon cable bridge that is for two cards. I have already asked tech support this very same question for my use.
  20. Ya I've been using the ribbon cable. And all that the link you sent me ( @scout) says is to check nvidia control panel for it so say SLI ( which it doesn't) however whats the chance that its the ribbons fault my comp is selecting SLI vs something else
  21. since those ribbon are made of tiny copper wires one could be break and the bridge wont work could you have a friend for testing both card and the bridge in is system then you find is bridge is good or the board is defective on that second pci-e slot
  22. Well I can pull both my cards out and test them on a friends computer with the bridge, but that still doesn't fix my broken pci-e slot which would allow them to operate at the speeds im lookin for as oppose to half that.

    When my friend has some free time Ill bring my cards there and test them out.
  23. that way you will know that if the card work together at 16x or go down to 8x since your board should handle them at 16x on the pci-e slot 1 and 2, result of good working means rma of motherboard for defect
  24. Yep, well im waiting for my psu to come in and see if its a watt issue. otherwise im just gonna assume its a mobo defect and send that in. theres no reason my video cards should work in every slot except my second pci-e 16x slot and sli doesnt work.
  25. we could go on after the psu will be in
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