Reddit.com: Question about the relevance of benchmarking

On Reddit.com there's a new post from someone relatively new to PHP wondering what the relevance of benchmarks is in a time when most performant sites use caching (full page or data) to increase their speed.

I was speaking to another PHP developer today who is a lot smarter than me. I was curious about Static Site Generators taking over the future of the web. [He] told me that most of the time, big sites have a cache that people hit. So people don't even have to wait for PHP to be interpreted. This begs the question . . . How are performance metrics relevant for different frameworks, when these sites are being cached anyway?

There's several comments on the post now with a few different opinions like:

• "Most of the benchmarks you'll see are dishonest and/or skewed as they don't paint an accurate picture of what's going on, or how they would be used in the real world."
  
• "As soon as you start taking too much time to return a page to a user you have a knock-on effect where you develop a queue of other users waiting for their page to be returned as well."
  
• "So far as performance benchmarks go, the framework and language used in your application becomes redundant once you add a caching layer as the page performance is then limited by what caching layer you use."
  
• "as a rule of thumb "logged out users see cached content" "logged in users see uncached content""
  

Link: http://www.reddit.com/r/PHP/comments/1n5ygr/i_am_an_idiot_question_about_the_relevance_of