I tried asking this on the Nvidia forums but surprisingly cannot get a straight answer. I'm wondering if anyone else out there is using three video cards - two in SLI and one for PhysX - without any issues with the PhysX card being recognized. I can dedicate the third card (a GeForce GTX 750) to PhysX in the Nvidia control panel and it seems to work fine. However, if I reboot - this card is no longer recognized as a dedicated PhysX card nor is it even selectable anymore in the Nvidia control panel. So what I have to do is one of two things. I can either disable then reenable SLI - at which point the GTX 750 magically reappears in the control panel as a dedicated PhysX card. Or I can disable/reenable the GTX 750 in Device Manager to get the same effect. I'm puzzled why I would need to do this as the GTX 750 appears to be just fine in Device Manager when I boot. It seems like it could be a driver issue (I'm currently using 353.30), but the problem occurs with older drivers as well. So now I'm starting to wonder if it could even be related to my motherboard somehow (a Gigabyte GA-X99-UD3P). In order to help diagnose the problem, I would really like to know if anyone with a similar arrangement using three video cards is not having this problem. That would tell me it's likely not driver-related. Of course, if anyone has a solution to this problem that would be just Jim Dandy but I can't find anything anywhere on the internet on how to fix this.