sometimes only a diagram will do:
You know it’s been 20+ years since I tried this coding lark, things have improved but not a lot. http://www.gaslampgames.com/2013/03/20/cpu-and-gpu-run-time-profiling-in-simulation-land/. Too many moving parts that all do their own thing. Parts get all picky about what they’ll work with and barely remember that if their stuff doesn’t join up with other stuff, it isn’t worth using. Wonder how many incompatible dodos “cornering the market” has bred during those years. Clearly I didn’t miss anything much. Appalling lack of progress – just like dentistry which remains painful and barbaric and hasn’t moved an inch forwards on that rather huge issue in thirty years either.
Here’s someone else’s take on it; his is much more interesting than mine, I may add: