Estelades and Progressive Refine in Cycles

For a while now, I've been wanting to create an image that would showcase some fun, alternative designs of the Catalan pro-independence flag—known as estelada. The image I came up with is pretending to be a natural-history museum kind of display of lapel pins typically worn by pro-indy folks—although this practice used to be more common back in the seventies than it is nowadays. I was inspired by a friend's piece of individual cereal bits displayed in a similar manner.

Coincidentally, while I was rendering this piece, I noticed something funny going on with the Progressive Refine mode. I have this app, called iStat Menus, to control CPU usage and temperature, and adjust fan speed accordingly. Anyway, I noticed a cyclical fluctuation in CPU usage and temperatures when using the Progressive Refine render option. The final image had a resolution of 1500x1200 pixels, and since I do not own a super-duper computer, this is quite a large scene for me to render. The cyclical fluctuation was happening coinciding with each sample being rendered. During rendering, CPU usage would shoot up, and the CPU would slow down in between samples. This rendering mode, I think now, is a good choice for those who are worried about burning out their CPU during rendering. Good find :)