There were four basic materials that the Egyptians used to build the pyramids: limestone, pink granite, basalt, and alabaster. Each type of material had a diverse use. Limestone had, for the most part, two uses.
To answer your question: The useful lifespan of a CPU is about 3-4 years. My guess on the technical lifespan under full load is closer to 8-10 years if nothing else breaks and takes the CPU with it. The reasons: High Performance Computing Clusters usually keep the computers for 3-4 years.
Battery life span is not set in stone. If your laptop's manufacturer made any claims about the battery's overall lifespan, it wasn't a solid, infallible figure. Your computer, battery, average use and computing habits all factor in when determining how long your battery will last. The Computer Hope website is a bit more optimistic, offering a time frame of two to four years, roughly 1,000 full charges. Battery Use.