GPU ressource peak from 0% to 100%

1.  Anyone is having the same issue? Trying to render with Rush with hardware acceleration on  and the GPU ressources will peak from 0 to 100 every seconds. It's been rendering for about 12 hours now and the bar has not passed the 1/4 time line yet.  File is about 12 gig. 
   
   

   

    

1. I have désactivâtes hardware accélération and tried again. Now rush is using my CPU and seams to render properly. Timer is only at 30m and goof down

my specs ; Ryzen 9 3900xt

32 gig ram 

2tb ssd

rtx 2060

thanks for your help