GPU Fairies.      The GPU Fairies are getting bored and lonely with nothing to do.  So they put your second card to work so that they won't feel left out.
 
Im not sure to tell you the truth.  I don't think there's anything resembling PhysX in this game that I know of.  Could it be possible that there is some sort of "spill over" to the second card?   Even though you don't have SLI enable, the PC still knows that there's a second card there.
 
 

Dukman
GPU Fairies.      The GPU Fairies are getting bored and lonely with nothing to do.  So they put your second card to work so that they won't feel left out.
 
Im not sure to tell you the truth.  I don't think there's anything resembling PhysX in this game that I know of.  Could it be possible that there is some sort of "spill over" to the second card?   Even though you don't have SLI enable, the PC still knows that there's a second card there.
 
 

I'll do some more investigating.

Zuhl3156

Yep, that's the same old Cait I have in Sanctuary. I gotta wonder if putting one of those hoods with hoses on her would shut her up. I haven't seen any 'Gags' laying around the Raider camps yet.

 
What I am wondering is if one gag will work on all. I have a robot companion and that thing won't shut up. At least with Dog Meat the ears got a break.

Just a little heads up to those that are playing the latest DLC or those that are getting ready to.
 
Without spoiling it you will need to do a save at each door that your robot companion can only open. When I got to the mechanist's chamber I ran into a problem and ended up reloading the last save several times before it allowed me to advance.

I keep getting a random crash.    Pretty sure it's one of the mods I updated, but not sure which one.  Might be time to start bug hunting again.  
 
Other than that, spent an evening building me a nice little shop out back with a walkway leading up to the door that those sticky fingered settlers don't like to use.   That'll keep em out of my stuff. 
 
And Im still 5 levels away from the minimum requirements for the DLC.  Yeah, I could jump in early, but I need to get a few more perks.

Dukman
I keep getting a random crash.    Pretty sure it's one of the mods I updated, but not sure which one.  Might be time to start bug hunting again.  
 
Other than that, spent an evening building me a nice little shop out back with a walkway leading up to the door that those sticky fingered settlers don't like to use.   That'll keep em out of my stuff. 
 
And Im still 5 levels away from the minimum requirements for the DLC.  Yeah, I could jump in early, but I need to get a few more perks.

 
Remove all your current mods and verify that you no longer get the random crashes. Then load 1 mod at a time for verification until you get crashing again. Then you will have determine if the mod is just bad or if it's a conflict between them and which one(s).
 
If you haven't played it yet, it's tough. Come prepared...........to die. LOL

Im hoping I don't have to go that far.   
 
I can narrow it down to the mods I updated over the weekend.   DLC's tend to throw a bit of a monkey wrench into things where certain mods are concerned.    Of course I could just not run mods.
 
Wait.  Let me think that one over...      
 
Nope.  Can't do it.  

I never tried any 'mods'. I guess we'll never know what I'm missing, will we?

Dukman
Im hoping I don't have to go that far.   
 
I can narrow it down to the mods I updated over the weekend.   DLC's tend to throw a bit of a monkey wrench into things where certain mods are concerned.    Of course I could just not run mods.
 
Wait.  Let me think that one over...      
 
Nope.  Can't do it.  

 
I hope that you find it right away also.
 
Not only DLC's but so do the patches.

Zuhl3156
I never tried any 'mods'. I guess we'll never know what I'm missing, will we?

I'm in the same boat as I never tried them either. I just remember all the horror stories that came with them and didn't want the headaches.