Ty_Murray :
Mousemonkey :
Other than using it as a PhysX adaptor there is very little to no point.
Dedicated Physx cards are what I've been seeing mostly as I searched around other forums and threads. I was curios as to how this works and what kind of benefit it actually would provide.
In nvidia control panel you can select what GPU you want to use for Physx processing.
Basically, in games that use Nvidia Physx, you should see a boost as it will be mean the main GPU would have less work to do.
Its not usually a huge benefit to be honest, but as you have the card spare, try it out.