No SLI

I got new had and reformatted it to GPT and installed win8.1. For the heck of it I installed the 2 980m cards I thought were dead. PC came on and both gpu were recognized in the bios. I installed the newest nvidia drivers. After installation only one card listed in device manager and of course no sli. Both cards are listed in the bios, and I know my sli cable works. Before I start going crazy opening and closing my PC is there something I can do to enable sli? Is it simple fix. Or, should I just send both cards back for new ones.

Thanks

 

And the driver you used is? The 347.09 and its later version appear to have trouble with maxwell SLI

 

There is something funny with 980M SLI that required some format and new installation of OS if I dont remember wrong. Several members here thought their SLI cable was broken too (Peter and the guy from Korea)

To enable SLI you right click on the Nvidia picture in the taskbar, "open Nvidia control panel", "Set SLI and PhysX configuration" and enable SLI there.

 

@D2 Ultimate I'm using 347.12. I even tried Mr Fox's driver from his modd thread. Only one card

@Cloudfire. I'm not that stupid. I know to enable sli I would go into the Nvidia control panel. There is no sli choice to choose

 

If you dont see second card in device manager then it may be not installed properly. Did you try scan for hardware changes?
It is worth try to clean secondary graphics port with compressed air or swap cards.

 

You wouldnt have been the first one to miss that option and you didnt specify that you tried that option out in OP. Thats why I mentioned it

Very weird if BIOS detect both but device manager only see 1. If no software does help I`m afraid you will need to get your hand dirty and reopen it and try Peter`s advice :/

 

It's strange that both cards are dectected in the BIOSbut not in Windows.

I guess I re-seating of cards and/or swapping would be better before attempting to get things right on a fresh install.

Still..very strange.

Have you tried uninstalling everything with DDU before installing drivers?

 

Hey Guys,

Thanks for your comments. This is what I have done:

I reluctantly took my pc apart and tried the GPU shuffle. I did discover that one 980m card is defective. When it is the MXM 1 slot I got uncontrollable white lines running parallel along my screen. The other card worked fine. I tried both cards in mxm slot 2 and got nothing no recognition. I panicked a little, but this is a new MB. I got out my 880 cards and tried them. One card in MXM slot 2 and nothing, slot one worked fine. I put both 880 cards in and both cards were seen in bios and device manager. The same thing happened when I plugged both 980s in.

Is this the way this is supposed to work? If the master (MXM 1) is not in, MXM slot 2 does not work? Either way I need a new 980m.

 

Yes, that's correct. The secondary PCIe slot cannot be used independently. You must have a GPU in the primary slot or it will not be detected.

From your testing, it does appear that one GPU is messed up. If one works fine in the primary slot and the other one does not, the one that does not work is no good. Some of our friends with 7970M CrossFire are used to going through this fire drill. Hopefully, the place you purchased the 980M GPUs will take care of that quickly. There have been several reports of defective 980M cards, so you are not alone.

 

Geez, with over 380 posts I thought I knew a thing or two. But, just when I thought I was no longer a noob something like this pops up. I wish I knew this before I spent so much time trying to figure out why slot 2 did not work.��

Thanks Mr Fox