Much of the measured time is a calculation that comes from internal postgres table http_requests which has a created_at and a completed_at timestamp. What typically shows is the difference between these two timestamps and from what I have seen, is usually quite close to the stopwatch time. What may be a variable though is if you are on a remote connection (i.e. at home), then there may be some additional time not accounted here, but I'm not sure. Something you can try is to add "?:render=false" to to the URL which essentially renders the dashboard strictly on the server and then pushes an image down to the client. See if this gets your time closer.