Can't see my second GPU

CPU: i5 2500k
GPU: 2 x his 6950 ice (1 is the turbo edition, one is the stock edition
mobo: asrock extreme4 gen 3
ram: 8gb g-skill
PSU: antec truepower 750w

hey guys.

just built my new system today and everything appears to be working fine apart from my second GPU.

for the life of me i can't get the second GPU to appear in device manager.

Both cards are working as i've tried them both in a single slot.

i've tried crossfiring the cards with each in the first position.

anyone got any ideas how to fix this issue.

17 answers Last reply
More about tomshardware
  1. Just tried the second slot on its own and there's no picture going to the monitor. Does this mean I got a faulty mono?
  2. Mobo*
  3. do you have the crossfire bridge on?
    power connectors to both cards?
    Crossfire enabled in CCC?
    Monitors are also to be connected to primary card only.

    from asrock manual:

    2. In CrossFireX mode or SLI mode, please install PCI Express x16
    graphics cards on PCIE2 and PCIE4 slots. Therefore, both these two
    slots will work at x8 bandwidth.
  4. Yes I've tired both one bridge and two cross fire bridges.

    2x 6 pin power connected to both cards.

    Cant enable crossfire in Ccc because windows isnt recognising there's a second Gpu.

    I've tried reseating the cards with no luck.

    I disconnected the card in the first pci-I express slot and just plugged the monitor into the second one.
  5. I am using pci-e 2 and 4. Appears to be the Dodgey one
  6. Might be time for a motherboard RMA. You've clearly tested that both cards work fine on their own and neither work in the second PCI-E slot. Just curious, did the fan power up on the 2nd card?

    EDIT: You might also try blowing out the PCI-E slot with some compressed air. If you haven't used that slot in a while sometimes dust can build up in there and prevent a good connection.
  7. Yes the fan is powering up. The mobo is brand new. Only took it out of the box today
  8. OK, I'd return/RMA the board then.
  9. one more thing to try:

    1-uninstall ccc from add/remove programs,shut down.
    2-remove second card,restart
    3-install ccc,shut down again
    4-install second card,start,recheck.

    Make sure the monitor is plugged into the primary card only.

    I've had this work for some others and actually once for me.
  10. One thing that's worth noting is that whenever I move the card slightly in the slot i hear a clicking sound. Tempted to take out the motherboard and check for broken points on the pci-e slot and re-solder them as needed. What's your opinion as this mobo is brand new.
  11. I'd say not worth it in my opinion. You may be able to fix the problem but you'll void your warranty if anything happens down the road and they notice it during RMA handling. That's even assuming you fix it now. If you can't fix it, you may be out a motherboard and have voided your warranty.
  12. Ok mate cheers. I'm in the process of trying earnies instructions. If you don't hear back from me then it hasn't worked and I'll have started the RMA process.

    Thanks for all the help
  13. Hey guys.

    I can't believe it but it turns out i didn't plug the molex power into the motherboard which powers the sli/crossfire (the molex connector was under my asaka voodoo cooler so i didn't see, FACEPALM).

    Only had half an hour before work but even after the plugged the molex connector in i couldn't get the card to appear in device manager.

    Things i have tried:

    1. uninstalling and re-installing drivers with both cards connected
    2. uninstalling drivers, removing card, re-installing drivers with one card connected, plugging in second card
    3. used one and two crossfire bridges

    Apparently i seen that PCI-E slot 4 only runs at 4x so it won't pick up a signal from the second slot.

    As i mentioned in a previous post the fan on the second card is spinning.

    I'm convinced now I plugged in this molex connector that it has to be a software related issue (although not positive).

  14. I know it shouldn't really make much difference but could the issue be because i got two different GPU's.

    I know they essentially the same with the only difference being a factory OC of 40mhz but would this cause the issues i'm having?

    according to this the motherboard doesn't support the 6950 in crossfire o.O
  16. The CrossFire stuff shouldn't matter. It should display in device manager whether CrossFire works or not even if it's on a slot wired for 4x (or 1x!). If it's not in device manager, then Windows can't see it. No CCC changes are going to fix a device enumeration issue.
  17. When i get home from work i'm going to reset the CMOS and then re-install windows with only one card connected. Should i insert the card after installing then install the drivers or install the drivers then insert the card?
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