[caf]

It is a misconception that RT means "lowest possible latency".

It actually means "latency with a known upper bound". The point of it is to be able to give engineering guarantees - the actuators on the rocket engine vanes will move within N milliseconds of the input voltage from the gyroscope module changing; the robot arm motor will be de-energised within N milliseconds of the laser perimeter sensor activating.

Bounding the worst case can often mean making trade-offs in the best case, and that doesn't make sense in HPC because the hard upper bound just isn't necessary in this environment.