This is on such a different level as to be irrelevant. The I/O scheduler will still try to accommodate requests within timeframes of seconds, at most. When copy

This is on such a different level as to be irrelevant. The I/O scheduler will still try to accommodate requests within timeframes of seconds, at most. When copying large files to/from two different areas on a spinning disk simultaneously, this means significant time will be spent flying the heads back and forth between them, regardless of the elevator. So queueing two 8GB movie files to go one after another will be significantly faster than copying them simultaneously.