Direct IO is only available in > ASE 15.0 or later.
ASE 12.5.3 is not certified with CIO who is very similar to Direct IO
Since we support both Direct IO - admittingly with 15.0 - and Quick IO, support of Concurrent IO is somewhat redundant.
on 12.5 has two choices in improving performance of file system
devices: raw and Quick IO.
For 15.0 customers there's a third choice: Direct IO.