Do GDE Variables Incur A Performance Cost?

Some customers have asked questions similar to:

Is using a lot of application variables bad for the performance of the application on the end device?

It's a fair question. Technically GDE variables do have a cost compared to static variables, but it is relatively minimal. It would likely be bad if you were to bind every possible field on every render extension in your application, for example. The reason for this is because these variables need to be resolved each frame. 

But if you are only binding 3-4 fields, while it would still technically have an impact compared to not having any variables, it would be much more minimal. Though any question related to performance will naturally depend on the hardware used.

At the end of the day, the best approach is to use a variable when it would simplify the process. e.g. if you had needed to swap an image many times over, you would want to use a variable as opposed to having a different control set to each image.