[rdtsc]

Thinking about it though, if you are assuming people are operating at that level and don't understand what the "free" means in this context, do you really think a simple explanation will all of the sudden enlighten them?

Using the analogy and talking about common knowledge in computer industry, this is basic enough that's the equivalent of "most computers need an electrical supply to work". If you are talking to someone about building a data center or scaling out a database and then you need to remind them that computers don't work based on unicorns but on electricity not sure if it makes sense to even remind them or continue the conversation.