How about 4 disk RAID5 array? I have a small database (3GB) in a small shop. The IBM 235 Tower backplane only holds 6 disks.I'm upgrading some of the disks from 32GB 10K RPM to 72GB 15K RPM. The backplane is controlled by a low end dedicated RAID card (IBM ServeRAID L4x http://www-304.ibm.com/jct01004c/sy...ocdisplay?brandind=5000008&lndocid=MIGR-59936 Current Config: Volume 1 = RAID1 2x 32GB 10K RPM SCSI (C/D drives for OS on C: and Log files / DB Backup Files on E. Volume 2 = RAID5 3x 32GB 10K RPM SCSI (DB only). We're installing a new software module (MRP) that will double or triple our database load. Would like to boost performance without bothering with a new box (this year). I only want to upgrade the RAID 5 portion of this solution and leave the OS / Log File volume alone (at this time) due to my time constraints. HOWEVER: The D: Drive is a little cramped, so adding a 3rd volume is tempting. So; I could do one of the following: I plan to use 72GB 15k RPM drives. 1. Make Volume 2 (E: drive) into a drive 4 disk RAID 5. 2. Make Volume 2 (E: drive) into a 4 disk RAID 6. 3. Make Volume 2 (E: drive) into a 3 disk RAID 5 + hot spare. Later, the hot spare could become spare for the RAID 1 volume (when / if we make it 15K RPM drives). 4. Add TWO Raid-1 arrays (E and F drives). E for the DB, F for the Log files and backup. My questions: 1. Since this is a very low end RAID card (Ultra 160 single channel), is the Drive RPM even the bottleneck? 2. Since there's only 3 striping drives (using 4 drive RAID-5) and RAID-5 is supposed to have more like 7 or 8 drives, does the rule "RAID-5 is better for the DB" still holding true? 3. Since this controller is only Ultra 160, and it controls Volume 1 as well (single channel), will I even gain anything from going to 15K RPM? Perhaps simply adding a 4th 32GB RPM drive (ie: another stripe) will be enough. 4. Is my money better spent getting a new controller and simply adding a 4th 10K RPM drive? Thanks!