Right now I'm running a GTX1080 ti ftw 3 as my main GPU for my 4k monitor, with an old GTX 770 in another slot to run 2 peripheral monitors for netflix / etc.
 
I've not been able to overclock the 1080 (crashes & artifacts at anything but default), but it operates fine without Precisionx open.  (just so we're clear I have made sure PX was pointed at the 1080 and not the 770 before starting the 3d apps)
 
So my stupid question is this:  Am I not going to be able to independently OC the 1080 so long as the 770 is also slotted?  I've tried to google the answer but it's practically impossible to find any answers about an asymmetric, non-sli configuration.
 
If it should be working then maybe I've got a bum card, or I'm doing something wrong.
 

Hello smeggles and welcome to the Forums!
 
Have you tried testing just the GTX 1080 Ti independently? Sometimes with different cards running in the same system will cause driver conflicts. If you haven't yet tried this then download a program called DDU, run it with just the GTX 1080 Ti installed, reinstall the latest drivers and run some tests.
 
There is also a new version of Precision XOC as of yesterday so I recommend updating that as well.

bcavnaugh
Welcome to the Forum
Are they un-chained or un-linked in XOC?

I'm unsure how to check that.  I'm familiar with XOC but this is the first multi-gpu setup I've run it with.  I've attempted to find a way to link them so I could maybe see how to UN-link them but either I'm blind or maybe it isn't an option for cards that aren't identical.  If you're referring to the Power & Temp target linking that references adjusting "all similar cards", Linked & Unlinked makes no difference - crash on both.
 

sajin
Sounds like the card may be boosting itself to its maximum clock speed already, and trying to overclock it further is pushing it over the edge causing a crash. What is the card boosting to when under load at default settings?

 
1936 MHZ @ ~ 60c.  I'm not familiar with what to expect with a 1080 ti just yet, but even a modest 100mhz increase still causes crashes / artifacting.  
 

EVGATech_JosephL
 
Have you tried testing just the GTX 1080 Ti independently? Sometimes with different cards running in the same system will cause driver conflicts. If you haven't yet tried this then download a program called , run it with just the GTX 1080 Ti installed, reinstall the  and run some tests.
 

 
Gathering that the answers I got weren't "No, you can't do that" then that was going to be my next step.  But before yanking cards out and clearing drivers I just wanted to ensure this configuration should theoretically work.  I will have an opportunity to do this tomorrow.
 
Thanks all for the help so far.

Sajin
The 1080 & 770 definitely won't be linked together inside precision xoc. 
 
1936 MHz is 253 MHz above the advertised boost clock (1683 MHz) for the FTW3. Your card may not be able to do above 1936 MHz due to silicon lottery.
 
What is the make/model/age of your power supply? Have you tried using the slave vbios on the FTW3 to see if it helps you get more than 1936 MHz?

PSU is EVGA Supernova 850 G2.  I hadn't tried the slave vbios yet, but if 1936 is a fair expectation for a FTW 3 I may leave well enough alone after I try the card solo just to ensure there isn't some conflict with my 770 causing the crashes.

Ha, no, I don't think I'll be losing any sleep over a 0.9% increase.  An extra maybe 1 frame per second isn't worth the trouble to me.  The card already drastically outperforms the 1080 non-ti I replaced, and that makes me happy enough.

 
Glad everything worked out.