Something Old, Something New: Extending the Life of CPUs in Datacenters

Datacenter operators are increasingly powering their operations with low-carbon energy sources such as wind and solar. As a result, the overall carbon footprint of datacenters increasingly comes from the manufacturing phase of server lifecycles. The most direct way to reduce the environmental impact of datacenters is to amortize the manufacturing emissions of hardware over longer timespans by keeping hardware in production beyond today's relatively short refresh cycles. In this paper we analyze the feasibility of server lifespan extension in datacenters using a series of microbenchmarks. We find that while newer processors outperform older ones, the difference is workload dependent, with some workloads showing promise for older CPUs. We also analyze the potential of incorporating overclocking to further extend server lifespans.