Thanks for your contributions guys. Very interesting.
A few days back, I read with anticipation skylimey's howtogeek link above on the subject of 'hardware accelerated GPU scheduling'. However, I tried both methods shown in the tutorial, first attempting the Windows settings method and next using the regedit way. Neither method gave access to any scheduling, so I am guessing it is a feature available only to some GPUs and not others.
I also experimented with browser controlled hardware acceleration (I'm using CCleaner's version of Chrome). Various experimental runs gave no consistent results, and just to prove the point I am right now running the Accuweather rain radar (lots of rain in Southern England right now) while simultaneously running 2 live railside feeds from railcam.uk. Lots of processing going on, yet most surprisingly, CPU load right now is only around 20%. My take on this is the likelihood that miscellaneous background processes such as antivirus and malware scans amongst others will run themselves silently at various times throughout the day causing resultant CPU load variations as experienced in my top post and thus making judgements of the effectiveness of any experimental 'tweaks' to balance CPU/GPU loads rather difficult.
I mentioned railcam.uk. Here is their take on hardware acceleration as mentioned in their troubleshooting section:
Hardware Acceleration - Turn it off!
This seems to be at the root of many playback problems. Fortunately, many browsers allow this to be turned off
So there you are.
And thank you also MechEngr for your really fascinating glimpse into the mysterious world of the GPU. Like most people I guess its something I seldom bothered thinking about as long as a picture presented itself on the monitor. But actually when I stop and ponder what's actually happening automatically 'under the hood' it all seems to be a minor miracle which for so long I took for granted. Things have come such a long way in home computing since my brother's
ZX Spectrum and my
Commordore VIC-20.