Blender Cycles Render Performance, Updating Shaders.

Hi all,

I want to know if there are settings which help reduce the time of the “updating shaders” and “Updating images” of a render.

I have seen a few times my .blend file scene render updating shaders and images being almost instant, and today without changing settings the updating shaders takes about 5 seconds per frame, which means rendering an animation is taking 5 seconds longer per frame.

Currently with 64 samples, its rendering a frame in around 8 seconds.
tho sometimes ive seen it render at 2-4 seconds the issue is the updating shaders…

does anyone has ideas as to how to improve this?