N/A just means that this statistic is not available to resolume, this does NOT mean that the gpu is not working.
The problem is that it's currently not possible for resolume to know on which gpu it's running (we can get the name, but that's not enough to know which device it is). For this reason, if there's two gpus resolume could be running on either and thus we dont know which device's statistics we should show.
This is also the main problem on osx because there you have the integrated gpu as well as the dedicated one.
If you see this N/A you can just do your vj'ing as you normally would and you have to rely on the fps meter to tell you when to take it easy.