GTX 970 Zotac and MSI SLI: "Maximize 3D performance" option unavailable in Nvidia Control Panel

Question

Attempt to pair a couple of GTX 970's with SLI is failing. One is a Zotac, the other an MSI.

From what I can gather from the many many posts I've read online now, the cards SHOULD be compatible. I do see both of them in device manager, and the SLI option is shown in NVIDIA Control Panel - but I can't enable it.

The option is just grayed out like this:

It shows this warning below the options: "To use maximum 3D performance connect the SLI-ready graphics cards with an SLI connector." I AM using a brand new bendy bridge though.

ATTEMPTS TO SOLVE INCLUDE:

• Reseating cards / Bridges
• Switching card slots
• Using a different bridge (altho one of the bridges I had did not say SLI on it, so I don't know if it's actually for SLI)
• Updating mobo BIOS
• Uninstalling & cleaning drivers and reinstalling them
• Looked for SLI settings in BOIS (there are none as far as I can tell)
• Switching to single monitor
• Using either top or bottom card for monitor output

I HAVE NOT YET TRIED:

• Another SLI 2-way bridge (I will once I can get my hands on one)
• 3rd party SLI software (not sure I want to do that)

BUILD:

• Windows 7 Ultimate
• GIGABYTE GA-Z97X-UD5H-BK - Black Edition
• ZOTAC GeForce GTX 970 - 4GB GDDR5
• MSI GeForce GTX 970 - 4GB GDDR5
• Intel Core i5-4690K Devils Canyon
• G.Skill RipjawsX DDR3-2133 C9 DC - 16GB
• XFX ProSeries XXX Edition - 850W PSU
• Samsung 840 EVO SSD - 250GB

Answer 1

Got it working!

It seems the cards were not compatible after all - at least not without som 3rd party help. I got them working together in SLI by downloading a small program called DifferentSLIAuto from this thread (V1.5 did it for me):

https://www.techpowerup.com/forums/threads/sli-with-different-cards.158907/

It's quite easy to install, but remember to follow ALL steps as instructed in the readme, including the test mode step. If you don't it won't work. Hope this helps someone!

Btw, V1.5 of DifferentSLIAuto was not on the GitHub page (only 1.0 - 1.4). For some unknown reason it was posted directly in the thread I mentioned - I don't remember which page, but it's there somewhere. Worked for me with Nvidia's 373.06 driver.