On a recent Vermont trip, I had the black box Pi setup and running. It was the standard setup as shown here on the site with GPS logging. In 2 days of driving from MA to upstate VT I logged 550 miles in the car and the Pi logged it all.
Ignore the 2 straight lines as those are the result of a bug in the PHP script used to generate the GPX files. You can use it here with your own GPS log.
There were over 30,000 GPS data points recorded over the trip. The default is 10 times a second to pull GPS data from the receiver and store it to the local SQLite3 database on the Pi before it’s synced to the server and removed from the device. In the future this would allow not only different frequency (which is user configurable upon setup of the Python code) but also an “automatic” mode that increases frequency at slower speed and decreases at higher speeds.