Yes, sort of.
Until Flight Aware goes exclusively to ADS-B data what you see here is based on ATC radar which typically updates every 6-10 seconds so the GS they have is an average over the last few seconds. Over the ocean GS is an average based on position reports which may only happen every 45 minutes or so. Again an average. When ADS-B/C is used the updates are much more frequent. As you have seen FA only gives you position graphs every minute, or oceanic reports as they happen.
By contrast the cockpit instruments are reading real time GS based on whatever sensor is in use, GPS, DME, IRU etc. In the cockpit GS variations of one or two knots every couple of seconds is common even in cruise flight. What you get here is esentially a smoothing out of data over a longer period of time.
