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.
Related Articles. Tech experts generally agree a computer should last anywhere between three to five years before needing to be replaced. Of course, this number is just a generalization and a number of factors play into lifespan, ranging from the computer's quality, care and room for upgrades. For small business owners, every new computer is an expense and an investment, one whose worth over time largely depends on how you use it and care for it.