https://sankethbk.github.io/blog/tags/microarchitecture/Recent content in Microarchitecture on Sanketh's BlogHugo -- 0.167.0en-usTue, 06 Oct 2026 00:00:00 +0000https://sankethbk.github.io/blog/posts/performance-engineering/labs/2026-10-06-lab-1-cpu-internals/Tue, 06 Oct 2026 00:00:00 +0000https://sankethbk.github.io/blog/posts/performance-engineering/labs/2026-10-06-lab-1-cpu-internals/<h1 id="lab-1-cpu-internals">Lab 1: CPU Internals</h1> <p>This is a hands-on report for the lab in <code>/home/sanketh/cpu-lab</code> on your Linux x86 laptop. It ties each experiment back to the ideas in <code>content/posts/performance-engineering/2026-10-04-cpu-microarchitecture.markdown</code>.</p> <blockquote> <p><strong>Important note about this laptop:</strong> the CPU is an <strong>Intel Core i5-8250U</strong> (15 W mobile part, base 1.6 GHz, max 3.4 GHz). Under sustained load it thermally throttles, so <strong>absolute nanoseconds vary between runs</strong>. The conclusions come from <strong>ratios</strong> and <strong>TMA buckets</strong>, not from chasing the exact ns.</p> </blockquote>https://sankethbk.github.io/blog/posts/performance-engineering/2026-10-04-cpu-microarchitecture/Sun, 04 Oct 2026 00:00:00 +0000https://sankethbk.github.io/blog/posts/performance-engineering/2026-10-04-cpu-microarchitecture/<h1 id="performance-engineering-cpu-microarchitecture-for-the-practitioner">Performance Engineering: CPU Microarchitecture for the Practitioner</h1> <p>This note explains what a modern CPU actually does while your program runs, and how to read that behavior through hardware performance counters. The goal is not to memorize every unit in a specific core design, but to build a mental model that makes <code>perf</code> output meaningful.</p> <p>If the previous note asked &ldquo;where does the time go,&rdquo; this note answers &ldquo;what is the CPU doing with the cycles it consumes.&rdquo;</p>