Does a computer fatigue during a long render session? Is that expected behavior?

Question

I'm wondering this in a general sense, for a PC and a laptop (rendering a set sample count). Currently I have an industrial fan blowing against my laptop, and earlier today I noticed 12 minutes a frame render times (after rendering for about 2 hours before, same setup throughout this), but later tonight (where temps in my home have not changed, and the fan has not moved), render times increased to 19 minutes. The scene has not changed perspective at all, and while I don't have the temps of the laptop on hand to compare both times, I wonder if the components inside still got substantially warmer despite the outside environment not changing. (I also did a frame render test at the very beginning of the above render, with and without the fan, and without a fan, render times were 15 minutes)

In a general sense, would there be render time fatigue, despite environmental changes being the same, for a laptop or PC? Like even a 5% difference? That is a lot less than what I'm experiencing but I wonder if this is a sound theory.

I have noticed times increased between frame 1 and frame 8 of a render on my PC, but the amount difference between frame 8 and frame 60 for example was either negligible or nonexistent (but I need to test this more). Maybe it depends on components, or just the fact that a PC is different from a laptop? Insight is appreciated.

Answer 1

In general, the difference in rendering times between frames can vary based on the complexity of the scene being rendered and the hardware components used.

For example, a scene with more complex geometry, lighting, and textures may take longer to render than a simpler scene. Similarly, a PC with more powerful hardware components, such as a faster CPU, GPU, and more memory, may render scenes faster than a laptop with less powerful components.

You can use software tools that monitor the temperature of the CPU, GPU, and other components