Help please. I added a second gpu, and system wont boot

[2941digger]

Please help me if you can. I added a second gpu to my rig and I cannot get it to boot.

I CAN boot with either card in the upper pcie16 slot. I cannot boot with either in the lower pcie16 slot.

Running ubuntu.

card 1 is diamond radeon r9 280x
card 2 is gigabyte radeon r9 270

mobo is msi fm2-a85xa-g43

i tried just about every setting in bios.

I CAN get video out of a card in the lower slot for bios, and to watch the boot crash, so i dont think the lower slot is bad.

getting AMD-Vi event logged [IOTLB_INV_TIMEOUT  device=4:00.0 address=0x000000014862a840

any help would be muchly appreciated.

[oxfardk]

try to use only one card
for example the diamond ones

[2941digger]

It doesn't take two cards to fail.

Either card in the lower slot and no boot.

Either card in the upper slot, mining.

Both cards either way and no boot.

I would suspect the slot, but i get video out for bios with either in the lower slot.

[Duane Vick]

Too much current draw off the mobo for those two cards possibly. You should get powered riser cards. Search on here for a guy selling 1x-16x powered usb pcie riser cards.

[AndrewGucci]

Could be PSU, or mobo, try to use risers from small pci-ex slots