Render cycle time increase

So here is my problem
i am rendering certain design and it gives me like 1 hour
and i do the same design but maybe little bit different pose and camera angle
and all same optimize render settings but whenver i do render the time cycle increse
i dont know why it all the same but it seems whenver i make new photo for same

design without adding new things and same optimize settings but it always increases and some time it says there is no enough memory
please tell me do i have to delete / clear something to get back on my avrage time cycle

i would really appreciate support
i have gtx 1070 8gb

Camera angle might increase/decrease render times depending on your scene. For example bringing camera closer to the object that has adaptive subdivision (microdisplacement) will probably increase render time.

So, can you provide more info about what kind of scene you have? Share some screenshots etc.

Thank you so much for reply and I will try to do that