If you disable RAID, then you will be using your drives in full SCSI mode - no RAID will be possible and no write cache will be available.  Switching between modes is NOT supported and will cause you to have to backup/restore to convert to RAID in the future. You can disable it by booting to BIOS Setup (F2), Integrated Devices and disable RAID. An alternative is to use the drive as an individual drive by creating a single-disk RAID 0.
How can we disable RAID on PowerEdge2600 and configure a single HD? Thanks
How to disable RAID 5 ON PowerEdge2600