Self-hosted Speed Test for HTML5 and more. Easy setup, examples, configurable, mobile friendly. Supports PHP, Node, Multiple servers, and more - librespeed/speedtest
Once every 6hrs would only be 180GB. A script that does it every six hours, but then increases the frequency if it goes below a certain threshold, could work well. I guess it all depends on how accurate you need the data to be.
True, although once per hour would still be a lot of data.
For example me running a fast.com test uses about 1.5GB of data to run a single test, so around 1TB per month if ran hourly.
Once every 6hrs would only be 180GB. A script that does it every six hours, but then increases the frequency if it goes below a certain threshold, could work well. I guess it all depends on how accurate you need the data to be.