How effective is using 2 graphics cards?

Got a demo of Neat 5, got the same grief and reported a bug to Neat support to see what wisdom they could offer;

> Used within Premiere Pro CC 2018 (on a nested sequence), despite leaving
> the plugin as using CPU only, it prevents PP from using GPU acceleration when
> rendering either timeline previews or final render through Media Encoder queue.
> With Neat disabled, PP rendered my test 60sec in 3 minutes and I watched
> both the GPU and CPU hit >90%.
> With Neat given 8 CPU cores to play with (deemed as optimised) I tried to
> render the same clip but it prevented Premiere from using the GPU; it hardly
> reached 5% and the CPU sat around 10% in task manager.
> 5 minutes later I could see in the preview that the clip timeline hadn't
> passed more than a few seconds and predicted render time kept getting longer.
>
> Disabled Neat and hit render = Full Power to Adobe again. It just seems to
> stop Premiere from using the GPU/CPU properly

I believe (based on our developers' experience with Adobe documentation, support, etc.) 

that it is a feature/limitation of Premiere itself. Premiere does not use its GPU processing

when certain types of plug-ins / video effects (including Neat Video) are used. 

We are not sure why Premiere does that but it is a decision of Premiere and its developers

and so can only be changed by them.

To efficiently use Neat Video with Premiere I recommend to enable use of GPU by Neat Video

in Neat Video Preferences. This should speed up processing because at least Neat Video's part 

of processing will be done faster.