Viewing render history per frame

Hi,

For my interior visualisation I am rendering out a movie.
One frame takes much longer than the other.
I am rendering images which I edit into a movie.
The models I use are partly imported from SketchUp and partly drawn in Blender.
We would like to find out what is taking the computer so long to render out one frame in 1.5 hours, while the other frame takes 17 minutes.

Ideally we would like to see the back-end of the process to see what is taking up the GPU power.
And if there is a way to see how long it took for each frame to render.
I use Blender version 2.93.

Many questions.

Thank you in advance for your help.

Are the frames before/after that one frame similar to the 1.5 hr one? whats going on in the animation for the long frame?