Defective GPU or MOBO?

[Octavialicious]

I've been going crazy trying to fix my stupid graphics cards. I have R9 290Xs in crossfire, and back when I had my FX-8350 they worked fine. But ever since I got my 4790K, I have had MAJOR artifacting. Here's the steps I've taken:

 

- Reinstalled the cards

- Reinstalled drivers (sooo many times)

- tried to use legacy drivers

- underclocked the cards

- put the bottom card on top and vice versa

- reinstalled windows 7

- reinstalled the cards again

 

 

that was yesterday

 

i got the drivers to work, but the artifacting continued. Here is what I think proves thats one of the 290Xs, and not the mobo

 

I put card one is slot one, no problems. I put card one in slot three, it worked fine. so this shows the pcie lanes are fine

 

i put card two in both slots, and it had artifacting in both slots.

 

am I in the wrong?

[CostcoSamples]

when testing card 2, you did it with card 1 out of the system, so card 2 was the only GPU?  seems pretty clear that card 2 has problems.  were you careful to avoid electro static discharge when installing?  did part of it get damaged by accident?  seems weird that it worked fine with the old setup, and is now crapped out.   If you have another system, or can get access to another system, try installing card 2 into that and see if the problems persist.  if so, RMA the thing.  

 

It's always good to test the defective part in another system, just to be sure.  If you can't, but are pretty sure, just RMA it anyway.

[Octavialicious]

when testing card 2, you did it with card 1 out of the system, so card 2 was the only GPU?  seems pretty clear that card 2 has problems.  were you careful to avoid electro static discharge when installing?  did part of it get damaged by accident?  seems weird that it worked fine with the old setup, and is now crapped out.   If you have another system, or can get access to another system, try installing card 2 into that and see if the problems persist.  if so, RMA the thing.  

 

It's always good to test the defective part in another system, just to be sure.  If you can't, but are pretty sure, just RMA it anyway.

I did, and Im positive  that no static happened.

 

I think the artifacting is happening now because with my new cpu, the card is being put to the limit and it handle it, were as before it was bottlenecking