According to the below white paper, they were able to get near-raw performance on AIX with the Concurrent I/O option: http://www-03.ibm.com/servers/aix/whitepapers/db_perf_aix.pdf I've also had good/excellent performance with concurrent I/O, but never compared it to raw so I can't really say how the two would stack up. ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of d cheng Sent: Thursday, July 20, 2006 10:11 AM I am writing a recommendation for one of my clients on using raw versus cooked filesystems for Oracle data files. Have you come across any recent documents regarding this topic? Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it.