Mac Pro RAID Card The Mac Pro RAID Card delivers enhanced storage performance and data protection through a powerful hardware RAID engine, 512MB of cache, and an integrated 72-hour battery for protecting cache data. The card occupies the top PCI Express slot (slot 4) of your Mac Pro (early 2009) and requires Mac OS X v10.5.6 or later. The Mac Pro RAID Card offers improved storage performance and data protection to your Mac Pro system — up to 553MB/s of sequential read performance in RAID 0. Ideal for video and creative professionals with demanding storage needs as well as for tower server applications, this hardware RAID option supports RAID levels 0, 1, 5, 0+1, and Enhanced JBOD. It has 512MB of cache and an integrated 72-hour battery for protecting the RAID cache. The card occupies the top PCI Express slot (slot 4) and connects to the four internal drive bays. To enable your Mac Pro for hardware RAID, install the Mac Pro RAID Card and two or more hard drives in bays 1 through 4. Each RAID level has minimum requirements for the number of hard drives: RAID Level Drive Requirements Benefit Enhanced JBOD One to four drives A non-RAID configuration with the ability to migrate to a RAID set at any time RAID 0 (striping) Two to four hard drives Maximum performance and capacity for the most demanding I/O requirements RAID 1 (mirroring) Two hard drives Maximum protection for critical data RAID 5 Three or four hard drives Data protection, high performance,, and efficient capacity utilization RAID 0+1 Four hard drives A mirror of striped drive pairs providing performance and data protectionThe Mac Pro RAID Card supports the creation of multiple RAID sets in a system and multiple volumes per RAID set. For optimal disk utilization in a RAID set, all hard drives should be the same size. Using Apple's RAID Utility software (included with Mac OS X v10.5), you can migrate the drives into a RAID set without reinstalling Mac OS X or reformatting the drives, and you can customize your RAID volumes to meet your exact requirements. Requires Mac Pro (early 2009) and Mac OS X v10.5.6 or later. Please note: The Mac Pro RAID Card occupies the top PCI Express expansion slot (slot 4) and you must have either all SATA or all SAS drives installed.