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Crossfire - 2nd card running PCIE v1.1 instead of v2???

Hardware:
P7P55D
i5-750
2x4GB RAM
R9 270X
HD7870
EVGA 750W

I try the GPU-Z rendering test to hopefully see the result of both cards running x4 v2, but instead the second card runs exclusively at v1.1 and the 1st GPU does't report x4 (x16) at all and it'll bounce between v2 and v1.1.

I've been planning to reformat Windows 10 because the auto-updates might have messed up the driver install order and my taskbar, cortana and keyboard commands stop working 'til I boot into safe mode and back (or it randomly works after reboot).

Can anyone help me understand why the xfire setup is running v1.1?
4 answers Last reply Best Answer
More about crossfire 2nd card running pcie
  1. can be a video drivers.try ressit the BIOS battery before unplug pc from power outlet
  2. Greg Gregorich said:
    can be a video drivers.try ressit the BIOS battery before unplug pc from power outlet


    I just reformatted and made sure to install chipset driver first, rebooted then installed Radeon drivers. Doing updates now.

    I already pulled the battery when I was in it earlier but after updates and config I'll clear CMOS and try default settings.

    I must mention I have a PCI Xonar DG in the bottom PCI slot, and OC's all around; CPU@4GHz, R9@1.2GHz/1.45mem, HD@1.2GHz/1.3mem tested and stable. Prime 95, furmark+plenty of DX11 games to crash 'em. RAM@stock (Mushkin Stealth 1600 cl9 1.35V).
  3. Best answer
    The motherboards in the i5-750 generation only had PCIe 2.0 max. In your motherboard if you have one video card at the main slot, it will run at PCIe v2.0 @ x16. The second PCIe x16 slot is really only a x4 slot. Also the minute you put a second card on that slot, the first slot drops to x8 speed.

    Sorry, I have an X58 chipset motherboard and it's old now. Time to upgrade.
  4. I agree. ^ Either it's really a v1.1 slot or maybe the PCI sound card has something to do it with it. Either way, I believe it's only a few % of performance lost. And I fixed my broken taskbar, Cortana and keyboard commands like alt-tab by installing Classic Shell. lol Thanks guys.
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