Worried about high CPU usage in CRIO

[Ether]

Having a high usage isn't necessarily bad. Well written code can consume 100% of the CPU ...

True. It's not unusual for safety critical embedded software to use all available leftover time to run background health monitoring.

Both loops are busy loops - they will consume all available CPU time to check to see if 500 milliseconds have elapsed

If you've got a 32-bit Windows machine, here's a simple demo why this is important.