Assuming that "caring about performance" = "you are in a tight loop": Here's a tool that simulates/visualizes instruction flow and data dependencies over multip

Assuming that "caring about performance" = "you are in a tight loop": Here's a tool that simulates/visualizes instruction flow and data dependencies over multiple loop iterations. https://uica.uops.info/ https://uica.uops.info/ Paste in assembly code, check "Trace Table" and run, then "Open Trace". Not sure if it will help with your annoying colleague, but it gives a much more concrete idea about how a processor will execute any given code. Or, if you want to channel their energy into something slightly more direct, there's also https://quick-bench.com/ https://quick-bench.com/ which allows easy micro-benchmarking. Still not guaranteed to be relevant to any real-world scenario, but more data-driven than "vibes".