Measuring Hyper-Threading and Turbo Boost

What this post added

This post details an experiment to quantify the performance impact of AMD's Simultaneous Multi-Threading (SMT) and Core Performance Boost (CPB) on Cloudflare's AMD EPYC 7642 processors. The experiment involved measuring requests per second, latency, and power consumption under simulated and production workloads. Key findings include significant performance improvements with both SMT and CPB enabled, with SMT showing particular power efficiency. The post also highlights challenges in establishing a baseline due to skewed CPU utilization in production and the trade-offs between performance gains and tail latency.