muulti gpu for 3d modeling/rendering

[TFProtoform157]

Whenever I look up whether multi gpu rigs are worth it, almost all results are about gaming. I know that having more than 1 gpu isn't super practical for games, but I want to know if it will make any difference when doing non-games stuff, like modeling or rendering in programs like maya. If there is some advantage to having 2 gpus, would it matter if they are in sli/eyefinity or not linked and just act like 2 seperate cards? I ask because I tend to rely on my gpu for most of the work (both in viewport and rendering), and my projects tend to be pretty big. 

[Crossbred]

It very much depends on the program, but many let you choose which cards to use and allow different types to be used together. It's not the same way that sli uses them, and in fact usually works better than sli in these scenarios.