Hi Fergal, that would only be true if you created your RAID10 array with twice as many disks as your RAID5 array, but in this case he said he had 5 disks configured as RAID5 and 4 disks configured as RAID10 so that means the RAID10 array can only read from 4 disks at a time, but the RAID5 can read from 5 disks at a time and should be faster if everything else is kept the same. Regards, Brandon From: Fergal Taheny [mailto:ftaheny@xxxxxxxxx] My understanding and experience is that raid 10 will be much faster for reads too because the data is mirrored and so reads can be done from both sides of the mirror and so read throughput is double that of a non mirrored stripe. ________________________________ 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. -- //www.freelists.org/webpage/oracle-l