SOLVED-Fatal1ty Z87 Killer wont use all PCIE lanes

You are running windows 10, was this an upgrade install or a fresh one? Your issue looks very much like a driver conflict. 

I do think it could be a driver problem, but its the Intel Chipset drivers for the Z87, not display drivers. The only info on reinstalling the chipset drivers I've found was that only a reinstall of windows would do this. Though I did try installing an older version and it does ask if I wanted to downgrade, but Windows still perfers the newer drivers (Good job Windows 10).

Chipset "drivers" are not related to this at all. They are INF files, not drivers, that simply identify the hardware on an Intel mother board.

Windows 10 upgrade, always questionable. Yes, you don't know what the upgrade installed until you check. Would I trust this type of installation? NO CHANCE! When Win 10 automatic updates are applied, you better check what happened, since it might include a new video driver, and possibly resets any configurations.

SOO many other things causing this, and many things to consider. Advice given above is valid and really quite basic. So is the following:

Yes, 16 PCIe 3.0 lanes in this platform. PCIe 3.0 lane allocation per x16 slot:

3 x PCI Express 3.0 x16 Slots (PCIE2/PCIE5/PCIE7: single at x16 (PCIE2); dual at x8 (PCIE2) / x8 (PCIE5); triple at x8 (PCIE2) / x4 (PCIE5) / x4 (PCIE7))

All of those three x16 physical lanes are not x16 electrically. From top to bottom, the three slots listed above are connected electrically as x16 x8 x4. The 16 lane PCIe 3.0 limit is then applied to each slot, depending upon the number of video cards in use. Which slots are you using?

Are you using any other cards in the PCIe x16 slots? With ONLY two cards in the PCIe x16 slots, the best you'll get is x8 x8. With PCIe 3.0, the difference between an x8 and x16 connection is 1% at best. If you have any other cards in the PCIe x16 slots, you'll have fewer PCIe 3.0 lanes for the video cards.

Windows Power Plan, Advanced settings. PCI Express, Link State Power Management. Must be set to Off if you want your video card(s) to not reduce their PCIe link speed at idle. Updating drivers can also change this. Clearing the UEFI/BIOS is needed to start over again.

In the UEFI/BIOS, Chipset Configuration screen, set the PCIe slots you are using to Gen3.

Are you following the instructions in your board's manual for connecting and activating Crossfire? Both for installation, and activating Crossfire with the AMD Catalyst Control Center software. No mention of this in your post.

Have you cleared the UEFI/BIOS since installing both video cards? If not, you MUST do so. While I listed this last, this is the FIRST thing you should do after installing any video card(s).

parsec wrote: Chipset "drivers" are not related to this at all. They are INF files, not drivers, that simply identify the hardware on an Intel mother board.

I'm giving up on this board. I Did a reinstall of windows, then installed the drivers and no crossfire setting available and the PCIE lanes where 8x for slot 2 and 1x for slot 5.