OMG IT ENABLED.  I will never reboot.

Power Off + Wait 1 Hour with the Power Cord Removed + (Power On + SLI) = No eBay
Power Off + Wait 1 Hour with the Power Cord Removed + (Power On + No SLI) = eBay
 

I got dishonored 2, played w/ SLI for awhile, worked great, when I got pulled away for a minute and left the game paused.
 
A minute turned into 30, and by the time I returned, windows had slept; the game couldn't hack it, locked my pc, and I was forced to reboot.  No sli.
 
I'll reboot 20 or so times, maybe it'll return.

Seems that you real issue is your Motherboard or Power Supply.

Reading over this thread I noticed the OP never did give the exact model of the two cards.
The GTX970 is a strange card. Not all are sli compatible with each other.
There is a list in the faq section that lists which model is compatible with what model.
Don't know if he bought the same model at the same time. Different models at different times.
 
He also said his were x16 gen3 but his CPU 3960x  I believe that is a sandybridge, he would have to force gen3 right?
Did he?
 
Maybe he will come back with answers to the mod#

I'll see if I can locate the model #s on the cards.  In the meantime, consider:
 
Sisoft Sandra sees both cards.  Windows, under device mgr, does not; nor does NV CP.
 
SLI *does* work sometimes, just not very often, and without any changes I'm aware of.
 
I bought both at the same time, same models AFAIK, from newegg I believe.
 
My bios was set to gen3 pci, which must be its default, as I don't recall ever having set that.  I tried forcing gen2 but didn't help.

Buying two of the same at the same time is a good thing.
 
I would set it to gen2 for now. The CPU itself does not support gen3 with out running some software.
Think it is called force gen3. Bill knows what it is, maybe he will chime in.
 
I just had an issue like this with my 2 gtx970 on an evga x79 board.
I get a chance I will go look in bios and see what I did to fix it.
I know setting it to gen2 was part of it

This is what bill1024 is referring to... http://www.evga.com/support/faq/afmmain.aspx?faqid=59534
 
SLI shouldn't work at all if you own cards that are in different columns.
 
If you do own two different cards that aren't compatible with each other it would be recommend to contact evga to see if they could help you exchange one card for another to get everything working smoothly. Another option would be to use different sli to force the cards to sli.

Hey thanks a lot, I'll check that out!

Back to cannot edit Posts the File is force-enable-gen3.exe from
http://nvidia.custhelp.com/app/answers/detail/a_id/3135/~/geforce-gen3-support-on-x79-platform