
That was definitive answer that it is working and impression of smooth framerate is not a placebo. When playing 480p or 720p video in browser, I run Resource Usage tool, where CPU load stabilized at around 50 to 80 percent (I had 100 percent before and getting choppy framerate). Then I made sure that official (non-free) NVIDIA binary drivers are selected in "Install Drivers" tool (third party drivers section).

Then I opened Synaptics Package Manager (Install/Remove Software) and made sure that libvdpau-va-gl1 is installed aside mesa-vdpau-drivers. At first, I run "Install Updates" from the start-up splash screen that shows up after installation, just to make sure all apps and drivers are up to date. I used GUI tools, which you can find via search tool in Whisker "Start" menu. I solved non-working video hardware acceleration in web browser this way, while no terminal commands were required. I am taking no further input on it, but if you feel you have a similar problem, start your own Thread and by all means link to this one. MODERATOR'S NOTE: I am posting this here as a "Stickie" because it is a good example of how older - legacy - hardware can get a new lease of life under Linux, and as a bonus, the OP (Original Poster) has solved his own problem.
