[littlestymaar]

If it's running in a consumer OS (not a RT one) and it counts on having enough CPU available to avoid missing the deadline, that's exactly what soft-realtime is.

Compare your “not a single click in an hour [for quality reason]” to a “not a single missed deadline in 30 years of the life expectancy of a plane, on a fleet of a few thousands planes [for safety reasons]”. That's the difference of requirements between hard and soft RT.

I did some soft real-time (video decoding) and I have a friend working on hard real-time (avionics) and we clearly didn't worked in the same world.

[AnimalMuppet]

Yeah. To me, hard real time is when you count cycle (or have a tool that does it for you), to guarantee that you make your timing requirements. We never did that.