I've been using RX570 GPU.
I've found some insert plugins in DAW makes GPU load more than 40%.
When I close visual window of plugins, GPU load goes down to 0% but make it visible, it goes up immediately without any audio processing.
these are plugins with problem :
Izotope RX breath control
Izotope Tonal balance control
My system info :
Windows10 home 64bit
samsung 850 evo
Daw: Cubase 10 , Studio one 4
I replied to this current AMD Thread about another User plugins not working correctly using Cubase 7.0. : VST Plugins have white screen
In that thread I linked to the company that created Cubase and there is a download link you can use to update your Cubase and some Plugins software to the latest versions. It also shows all versions that are compatible with Windows 10.
Here is iZotope Support that might help, that is if you are already aware of this site.
Maybe updating Cubase to the latest version may help the plugins to work more efficiently like it did for the other User of Cubase 7.0. Or open a Support Ticket with iZotope Support and see what they recommend.