This work explores systems where source updates require multiple sequential processing steps. We model and analyze the Age of Information (AoI) performance of various system designs under both parallel and series server setups. In parallel setups, each processor executes all computation steps with multiple processors working in parallel, while in series setups, each processor performs a specific step in sequence. In practice, processing faster is better in terms of age but it also consumes more power. We identify the occurrence of wasted power in these setups, which arises when processing efforts do not lead to a reduction in age. This happens when a fresher update finishes first in parallel servers or when a server preempts processing due to a fresher update from preceding server in series setups. To address this age-power trade-off, we formulate and solve an optimization problem to determine the optimal service rates for each processing step under a given power budget. We focus on a special case where updates require two computational steps.

翻译：本研究探讨了源更新需要多个顺序处理步骤的系统。我们对并行和串行服务器配置下不同系统设计的时效信息性能进行了建模与分析。在并行配置中，每个处理器执行所有计算步骤，多个处理器并行工作；而在串行配置中，每个处理器按顺序执行特定步骤。实践中，处理速度越快对时效性越有利，但同时会消耗更多功率。我们识别了这些配置中存在的功率浪费现象，即当处理工作未能降低时效信息时发生。这种情况出现在并行服务器中较新的更新先完成处理，或串行配置中因前置服务器产生较新更新而导致服务器中断当前处理时。针对时效性与功率消耗的权衡问题，我们构建并求解了优化问题，以确定在给定功率预算下各处理步骤的最优服务速率。本研究重点关注更新需要两个计算步骤的特殊情形。