Hi Rasmus,
When P3 measures your performance, this is called profiling. What it does is track every function call that WordPress core, plugins, and your theme makes and measures the time it took, and traces it back to the file it originated from. This measuring & tracing takes time. The overhead of measuring and tracing is called the “profiling overhead.” Say your site takes 1 second to load normally, when it’s actively profiling (or “scanning”) this time may go up to 2 seconds or 3 seconds. These numbers are just examples and they depend highly on your server and website configuration.
So, in your numbers, your TTFB is represented by this number:
Site Load Time 0.6084seconds avg.
And the reason the profiling overhead is so high is because you have a lot of function calls happening:
Number of PHP ticks: 6,320 calls avg.
A tick is like a function call or a WordPress hook, but that’s a grossly simplified explanation. You can just think of a tick as “a thing that happens that requires processor time.” Generally more ticks means more time. Again, that’s grossly simplified. Please don’t focus on optimizing that number too much, it just shows what P3 is monitoring that’s taking so long.
I would suggest doing a few things:
* Doing a manual scan by clicking “manual scan” and using a second browser to surf your site (make sure you’re logged out in the second browser). Then click “finish scan” in the first browser. This will give you more accurate results for an anonymous user.
* Try to lower the # of SQL queries. Use some of the other graphs to figure out what’s going on or toggle plugins on/off and repeat the scan until you figure it out.
* Try a caching plugin. P3 won’t work with caching plugins, but tools like webpagetest.org and tools.pingdom.com will give you a good load time score
* Try looking for ways to lower your overall render time. Tools like webpagetest.org and tools.pingdom.com will give you hints if you have too many external scripts, or too many images, etc.
Hope this helps!