We are running Sybase ASE on a P670 16 cpu 24 GB Ram. Our question is about disk access. It seems that Raw devices are accessed through fastpath and FS is accessed through AIO. All of our databases are on RAW Devices. We are not sure if fastpath is Asynchronous or not. Does anyone know the answer to this? Our gut tell us to disable fastpath and use AIO through the OS. Any help would be appreciated.