JD's Auto Speed Tester is a tool which will automatically test and report on your internet connection performance over time.
Just leave the program running in the background and it will regularly check all your key connection parameters: upload and download speeds, ping times, packet loss, jitter and more. This data is displayed in a chart, and also logged to a CSV file for easy analysis later.
JD's Auto Speed Tester is highly configurable, so if any of this doesn't suit your needs then the chances are it can be changed. You're able to set custom servers for the upload and download tests, for instance; you can choose which server to use for the Ping test; and you can tell the program not to run its tests at all if particular programs are active.
For all this power, though, JD's Auto Speed Tester uses only minimal system resources. On our test PC, for instance, it needed little more than 1.2MB RAM when running in the background, so should run without problems on most PCs.