PCIEx16 speed problem with dual HD5970.

I have two HD5970 installed in a P6T SE motherboard in the two blue (x16) pcie slots and 2 out of 4 gpu's appears to be running at x8 speed given the information taken from ATI ccc and EVEREST ULTIMATE. I have the latest drivers (windows 7 64/ATI catalyst 10.2) and no RAID configuration (if that matters). I also have an i7 975 (stock speed). A single vga card also runs in both gpu's at x8 speed (installed in the first pcie x16 blue slot) instead of x16 speed. Is there a BIOS setting i need to change or something else?Any help would be appriciated.
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  1. i had some problems with my 5850, sometimes it was on x16 but it kept changing between x1, x4, x8 and x16 depending on its mood lol but i solved the problem by changing PCI-E Frequency in bios from 100 to 101. notice that i dont have a pci-e x16 2.0. i have only pci-e x16 1.0 or 1.1 whatever its called :P

    maybe you should try the same thing :)
  2. I have pci-e x16 2.0 and i just tried changing the pci-e frequency. No such luck though. It keeps running at stable x8 speed. Thanks anyway to Derbixrace. Any other thoughts would be welcome.
  3. maybe reset the bios?
  4. I have tried reseting the BIOS in the past without any change i'm afraid.
  5. maybe faulty pci-e slot? sorry but im running out of ideas, someone with more knowledge should help you out :)
  6. Derbixrace said:
    maybe faulty pci-e slot? sorry but im running out of ideas, someone with more knowledge should help you out :)


    Having a faulty pci-e slot was exactly my original thought. Thanks again for your response.
  7. Have you tried reseating the GFX cards, both of them? Have you also made sure to check the users manual to make sure those are the right slots to run crossfire in?
  8. Truhls said:
    Have you tried reseating the GFX cards, both of them? Have you also made sure to check the users manual to make sure those are the right slots to run crossfire in?


    Yes i have checked all of this. No luck...Note that i own 2 XFX cards.
  9. makone said:
    Yes i have checked all of this. No luck...


    One thing this board does not support currently is NVIDIA's SLI configurations, which is their multiple GPU solution for improving game performance. Three-way Crossfire is supported as well as ATI's CrossfireX with two 4870 x2s


    But it didnt list anyhting with 5970's. maybe try a bios update?
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