I was working in cycles for something I need better photorealism and passes than eevee. It is 25 seconds of animation. I started rendering before going to be last night. The render time was around 2 minutes per frame. I watched as the reading above the render quickly went through the "updating shaders" step. When I check on my computer this morning I saw that I was getting 4 minute renders and the "updating shaders" step was holding for much longer. I stopped the render after a a frame and then rerendered the same frame after giving the computer a thirty-second break. The render time was back to 2 minutes. I noticed this a few days ago when rendering in cycles. I thought it was a problem with the batch file I was running to render multiple documents. It seems, at least in 2.8 cycles, the updating shaders process has a terrible creep to getting longer. I have 32gb of ram and was only using about 15% of it while rendering. I wouldn't mind a solution to store the shader info on RAM. Why does this creep happen? What is the solution?