Iteration
 

How long does 1 Iteration (Iter) represent in Star-CD? 1 minute?
My CFD model returns different heat pattern at ITER=1000 and ITER=1500.
Thanks.

transient or steady case? timestep==??

You didn't really understand what steady state means, did you? Did you ever in your live hear a CFD lecture?
An iteration does NOT represent any time. When running a steady state case, the converged solution will represent the state after an infinite long time. Even worse, every cell might be on a different (virtual) time level, so a steady state solution just makes sense when it's fully converged. It is NOT possible to pick the solution at some different iteration counts and compare them except for fools.
When your solution changes when the iteration advances (assuming you're running steady state), it is not yet converged. Keep on iterating until the solution does not change anymore. When it takes long, it takes long. But you need to run until the solution does not significantly change, everything else is just bullshit!